Secretly the BEST Filter? Why the Under Gravel Filter rocks! 

I've kept fish for 60 years. When I started there was only under gravel filters. I had never problems with plants or fish. THen the revolution came with the new filters, and I started using them. Along came a lot of work and problems with fish and plants. A lot of upkeep... I just started a new tank, made myself a under gravel filter. Clear water, happy plants and fish from day one! FUNNY story: Many years ago, a tank with under gravel filter, I had 2 Kuhli Loaches. One day I could only find one of them and thought one had died and been eaten up by the rest of the crew. 6 months went by and it was time for a major clean up. And in the slurry under the filter the Kuhli turned up. Happy as a clam! It had probably went down the irrigation tube and never seen the need to get back in the tank.. LOL

I used one when I first started fish keeping, but was convinced via RU-vid videos that it was outdated. I will most likely go back to it when I move. I really liked using it. My water stayed so clear.

I have quite a few tanks running ugf. 2 have been set up close to 20 years and are the most stable tanks i have. Only been broken down once and that was to move them from my grandparents house to mine. Those 2 tanks had been running probably 10 years before i moved them and to this day i have 0 issues with them. Plants grow like crazy, fish are happy and breeding, parameters stay rock steady and inly get a water change every 3 months.

I’ve been using sub-gravel filters since I was 10 years old, I am now 70, and yes, I’ve utilized many other methods of filtration or different purposes but if I had to get rid of all of them, there’s only one I would want to keep a sub-gravel filter, they’ve always been the best overall, but it took me a while to figure that out.

While I'm not an old timey fish keeper, I am sold on UGF. I went from canister filtration, to trickle filters, to sponges, to settling on UGF. They keep my tanks so darn stable despite heavy feedings with fluctuating stock levels as the number of fish increase or decreases (breeding fish & growing fry). I've slowly converted all my tanks over to air-driven UGF & I can't see myself changing back anytime soon. Additional upsides for me outside of their function in the tank & how low maintenance they are in general: 1- In todays economy, it keeps the running costs of multiple tanks right down because I'm relying on a low watt air pump to power all the filtration. 2- It's simple to keep going during any power outages. 3- They are cost-effective due to how durable & inexpensive they are to repair or replace in the event it is required.

I would appreciate another video showing how to use a UGF, set it up to get the best results, talk about size relative to tank size and where to buy. I only see one size in stores.

Since the early 80's with my first tanks, until i recently dove back in, i use an ugf and a hob. I set up the ugf and never think about it again. Its just there. About 3 months into my most recent aquarium enthusiasm, i found a bladder snail that mustve come in on a plant. After reproducing like crazy, we slowly moved them to their own 10 gallon with a female betta. We got them all except for one that got into one of the two ugf tubes and, with the screen on the oulet it got to big to get out. It goes back and forth under the gravel to clean the algea in both tubes. If it has babies and when they leave the tubes, we pluck them out and put in the 10 gallon. We sont know if the snail in there now is the original, but some specialty crafts are handed down to the next generation.

You can also hook up a hob to pull through ugf.

When my family kept fish in the late 60s through the 70s. We started out with box filters and then moved on to Metaframe Dynaflow HOB filters. We had a 15 gallon, and two 10 gallon metal framed aquariums with slate bottoms. We successfully bred angelfish in the 15 gallon, and raised the fry in the 10 gallon tanks. Once they were large enough, we sold the juvenile angels to the local LFS. One the subject of UGFs, one great thing is that the lift tubes are fairly unobtrusive at the back corner of the aquarium...

Glad to see this video after the previous one. You covered most of the bases well. Here's one BIG benefit of the UGF that you didn't mention: It will NEVER spring a leak. If your UGF springs a leak, it's because the tank sprung a leak. That alone makes it superior to any canister filter I've come across.

I am a huge fan of under gravel filters. They are awesome with planted tanks, back in the day when they were common I had a 55 gal. planted community tank along with 20 and 2 10 gal. aquariums. The water was crystal clear, plants grew like weeds and the fish flourished. I received many complements and I used tiny natural gravel. One day I hope to have space for another large tank, built in would be nice. I suggest keep the under gravel filters they are amazing. With or without other filtration systems.

Bentlry, you are so right, the under gravel filter is excellent for plants. I have always used one, from my 45 gal planted fresh water tank that grew so many plants it paid for my hobby, to a 230 gal salt, cold water, tank I hade to make a homemade undergrave filter that was powered by a secondary canister filter in the room behind the tank. It was so good crabs would hatch their babies and the baby crabs would live and grow in the gravel and under the filter itself. I maintained that tank for 15 years that way. Up in Sitka Alaska elementary school.

Thanks for this great video. My 1st tank, a 10 gallon, was powered by an underground filter. I was 10 years old and it was 1968. It worked great. I knew very little. I probably overstocked the tank. I had completely forgotten about this type of filter. I am now planning a 140 gallon planted tank. I am seeing this video just in time! Thank you!

I now find myself inspired to replicate my very first 10 Gal aquarium from 1980. It did work, and it was very cheap. I recall my riser tube even had a pocket for activated carbon. I didn't know why it worked back then, but this explained a lot. I sure appreciated your explanations of the other ways to improve this simple setup.

Every one of my tanks has an under-gravel filter, along with either a canister or HOB filter. I am a FIRM believer.

I m all in, will use one on my 85L master nano-communal project

Old school here… had a lot more success with undergravel & hob combo filtration & fluorescent lighting on my aquariums back in the day than compared to the new stuff I’ve purchased.

UGFs are great. My only hang up is the lack of access to the area under the gravel plate but aquariums have run on UGFs for thirty years without an issue so you can't argue with success.

40 years ago I kept a 4' tank with 2 undergravel filters with a powerhead for each, WOW, plant growth was such that once a month I had to thin it out, healthy tank no disease issues. The power heads provided the best aeration possible, falling water makes the tiniest of bubbles, water changes were not necessary, top ups was all I needed to do. In my opinion these filters became 'obsolete' simply because the retailers had no return customers for filter parts.

I have been running an undergravel filter for about 10 years now, cleaned the tank once in that 10 years. Water parameters are always stable, just high nitrates. After a set it up the second time, I put matrix in the bottom part of the filter and put a weed cloth on top, nitrates are looking better now. I do water change every week or every 2nd week, just because I want to not because I need to. I am from South Africa. I set up 2 of my breeding tanks now with undergravel filters. I am glad you woke up to the benefits of undergravel filters, but hope not too many people do that, otherwise I am sure the price of them will rise.😂😊

I've been fishkeeping since the early 80's. I think I've tried every single type of filtration. I'm sold on UGF! Simple, efficient, effective, nothing else to buy after the initial setup.

Yeah, I'm that weirdo who mixes old and new school together. I have a showroom-tank wannabe like aquascape with both an undergravel anoxic filter that runs on air (set to run only when the lights are off, something the Japanese do for airation purposes) AND a canniater filter for water polishing (that isn't connected to the under gravel filter.) Is it overkill? Heck yeah, but I love it :)

I have been using ugf with power heads on a 55 gallon planted tank with discus and a 40 gallon reef tank for many years and both are super stable and healthy !

Hey Bentley. love your stuff. I used a U.G.F. on a 29 tall back in the early 80s. I had Amazon Swords & Jungle Val that did pretty good, not great, but ok. even with a weak crummy old florescent light from a hood kit & all in one liquid fert.. These days I have a 20 tall with a Fluval 3.0 light and a Co2 Art Pro SE & in-tank diffuser. I have 3 inches of Eco complete for substrate. & even with all that fancy hardware my Swords are not doing so well. I switched from Co Op Easy Root Tabs to Seachem Tabs and Easy Green. I expect the Seahem tabs to work better. too soon to tell .. I remember the plump white roots I had with the UGF years ago & have thought about going back to UGF. after seeing this video. I completely agree with all you've said here. it all makes sense & I know from previous experience UGF works .. I just ordered a Lee Original UGF plate and bought an Aqua Clear power head. with the Eco Complete & all the other fancy hardware I expect to be trading Sword plants & Sword Tail fry @ the local fish store soon. I'll let ya know in a while how it works out. Stay Awesome.

Hooking it up to a canister filter was brilliant... sounds just like Dean... perfect DIY combination!

Hi Bentley I thought you got crazy on your last video on terrible under gravel filter almost everything you were saying was wrong I have been in the hobby for 50 years and have run them in fresh and salt water tanks and had great success in both for many years the salt water tanks I had power heads running on them. I loved using them. I also set up my friends fish store for him and I used all under grave filters and a small tetra HOB on every 75 gallon ,40 gallon, and on all the 20 and 15 gallons tanks for about 20 years they were running so now hearing this video it really makes sense to me I like you now again hahahahaha unfortunately my 15 tanks running now have none it’s funny how people go with the trends i am into very natural planted tanks deep sub base and cap it with sand but getting the desire to start using them again the past year 15:34

Thank you sir for the explain undergravel filter. Now, i choose undergravel filter for my tank. Im from indonesia , and last thanks you very much 🎉

OMG! I didn't even know the UGFs were still made. I just spent 2 hrs listening to reviews on the newer filters available. I'm 74 and plan on setting my 20 gal long tank up after I get moved to Fairbanks, AK. Back in 1971, I bought a 10 gal setup for my first aquarium at Rich's Discount in Atlanta, GA. I asked a lot of questions and decided on the UGF they sold way back then. I also wanted it to be a salt water tank and had wonderful success. I had a few live rocks, a seahorse and something else. I was so surprised one day that the seahorse (male produced babies. One day I had little jelly fish appear. I had casualties though, as my uncle had 2 150 gal tanks and was raising brine shrimp. I allowed the shells to get into my tank and they stopped up the stomachs of the seahorses. The tank was so well balanced even for a 10 gal and my UGF looked just like the one in your video except it was white and I had about a half inch loosely woven mat that laid on top of the UGF. On top of that was the crushed oyster shell. The part I'm fuzzy on was the UGF was hooked up to an outside filter that maybe the power air tube fed?? Maybe you can refresh my memory on that part because I think I will go back to this after I move. Wonderful review from North Texas

LIVE LOVE LOVE undergravel filters!

Undergravel and Matten filters are definitely my go-to filtration. If the bio load is extreme, I will give in and use a canister filter with a Matten filter as the pre filter. I do love the knowledge you share and enjoy seeing the methods you use. This series is a very shock and aw series that isn't my cup of tea. Regardless of my opinion, I do hope you are able to achieve your intended goal. 😊

I totally agree! I dont know what it is about a lot of people in the hobby that makes them so confident that they know it all and they can be so wrong. Its unreal sometimes. Cory from aquarium co op said the same thing that the undergravel filter is a great filter. Im about to start my first planted tank and im going with the undergravel filter in a 29 gallon tank. Ive always just had cichlid tanks but ive always thought the planted tanks with small fish were beautiful so im trying to learn about how to do it before i get started.

I well remember, back in the 'old days' of the 60s and 70s, the belief that plants and UGFs were not compatible. Of course, keep in mind, that in general, we hobbyists had no idea about beneficial bacteria, much less the hydrogen cycle. The result being no water testing for ammonia/nitrite/nitrate and no chlorine to worry about. The only thing was to use water from an established tank when setting up a new one. I certainly never heard a scientific explanation for that, it was just the norm. My, how things have changed!!

Always loved an under gravel filter and after watching this I'm gonna order one for my 2 foot tank

My very first aquarium had a UGF driven by a powerhead. That tank was set up for so long that by the time I bought my second aquarium, all the stores had quit selling UGFs and the salespeople told me they were obsolete. I guess what's old is new again. The next time I re-do my tank, I'm going to try to achieve anoxic filtration with a UGF/plenum setup.

Thank you Bentley, I've inherited 3 aquariums with fish & they had been neglected for a long time. I'm keeping everyone alive in buckets now, but I'm planning to set up all of them with UGF & a HOB. I really appreciate the biological approach. Thank you again!

This is the filter I grew up with. We only did a full break down of that tank about every 2 years along with regular water top offs, and a little gravel vacuuming here and there. The tank wasn’t over stocked and it was a very enjoyable low maintenance system… with clear water and healthy, long lived fish.

Bacteria is a single celled organism; that cell is not a brain cell. It doesn't care what it grows on. The entire volume of the substrate provides just as much, if not more, surface area for bacteria to grow on than an Aquarium Co-Op course sponge, or canister filter. Over time, soil compaction and settling can cause microclimates of restrictive flow and oxygenation levels through the substrate and UGF so that different colonies of bacteria (e.g. anoxic, or others) can develop over time. Both bacteria and plant roots are immobile. They can't get up and walk to the fridge to get something to eat. They both need the water current to bring nutrients to them. I wouldn't recommend putting ehaim bioballs or whatever under the filter. You're just making more restrictions for the flow of water through the volume of substrate above it.

You just gave me a massive amount of ideas to work on!

I remember when I was a kid in the 90s and wandered into an aquarium / fish shop and the old korean shop owner was preaching about how this is the right way to do it. Explained how the plants feed off the waste and in turn helps cleans the water. Saved up money and bought my first setup there.

Under gravel filter ...Guaranteed success low cost

I have an undergravel filter attached to my Fluval 407 on my 75 gallon with about 4 inches of substrate. Plants love it and the 407 never slows down. The substrate is an amazing prefilter that keeps my 407 happy.

Thanks for the great video about UGF! There is a problem Undergravel filter that the UGF has narrow slots in the plates, which over time become covered with silt and dirt and cannot allow water flow through them. And if aquarium tubes can be easily cleaned with a brush, then I have no idea how to clean the narrow slots of the UGF. I will be glad if the author removes my fears!

I said it in your last video criticising the ugf, I have just the one tank with one of them and it’s my least troublesome tank. Avoid sand substrate and they work to their strengths. 👍🏻

I grew up with a UGF and loved how simple it was versus filtration methods that required more effort or expense. I recently saw a "bog filter" being used by OzPonds and applying it to a USB solar powered pond. It's funny that I haven't really seen UGF for ponds as I re-enter the hobby, even just for small ones. I'm tempted to start with a sponge filter with a single air-stone, but wondering if I can find a UGF plate that would suit the situation just as well. The deepest part of the 40 gallon resin pond has an area where a UGF would fit nicely. I kept thinking a UGF would work well for a pond intake bay, but there's no area for a UGF plate to sit flat. I just cobbled some mesh material and rocks around the pump in the intake bay to function as a UGF. Update: Solved with a fabric pot loaded with media and a center uplift tube powered by an airstone. (semi-undergravel filter in some videos, although the fabric pot is my take on it.) An undergravel filter in a tray or pot with uplift tube surrounded by whatever media you see fit is all you need. When I grabbed the fabric pot to change something out, it did make a mess since things weren't as contained. A tray or flowerpot may be better if you just want to lift the whole thing out intact for any rework or cleaning.

This was first filter I build myself when I was 10yo. It was just a piece of wavy plastic roofing that granddad gave me. I used saw to make narrow holes into it and clear pipe as output and place for airstone. Few tiles under it for better ground clearance and flow. Best filter I ever had.

I would be one of those old guys who's been running UGFs since the 70's. Old school Eheim canisters do a great job of pulling water through these and plants love it !

Ok, you are back on the "I Love This Guy" list!! I know the rules of This Sucks - This is Best and I totally get it. I am an old guy and free up with UGF and will always stick with it. I do like sponge filters and Tidal HOB filters, but never without my anoxic UGF setup. I generally run two filters on every tank just because and one is always always always UGF. Just so you know that you are on my favorites list, I a 15:06 m part of Cory's ACO FB forum for beginners. So many questions about filters and plants and I almost always tell them what I learned from you or Cory AND point then towards a video. Specifically plants. Any is mine brown, any the holes in leaves, why the crispy yellow edges, ect. Please keep the content rolling my friend. But don't ever talk bad about UGF again 🤣🤣🤣🤣🤣

I had a 55 gallon filtered by an UGF with 4 lift tubes powered by power heads. Inside the lift tubes I had stacked API BioChem Stars. Worked great.

My 90 gallon show reef tank had undergravel filters. I had 5 inches dept of crushed coral and over 100 pounds of live rock. I used two canister filters connected to the undergravel tubes. It lasted many years. It ended up with one canister just for charcoal for clear water, and a powerhead on the other side. After getting fish that ruined my live coral and anemones, it made it into a trigger fish/eel tank. A 5 gallon buckets worth of crushed corral over an undergravel filter is a massive amount of biomedia. My Clown trigger was almost 8 inches in length. When I finally took it all down, there was quite a bit of gunk under the filter.

I agree 1000%… I ve kept massive bio load with huge cichlids and never crashed my tanks.

I have mine a 25 gallon set up with a huge piece of sponge as a substrate and undergravel filters underneath. It's essentially a horizontal matten filter. I haven't cleaned it in 1 year and 6 months it has been running other than the occasional light siphon vacuum on the top facing side of the sponge substrate. It is also connected to my DIY fluidized/canister hybrid using 2 gallon sprayer bottles(the one they use for spraying plants insecticide/fertilizer). It essentially acts like a pre-filter like what Dean is using them for.

Great video! I wish you would have touched on gravel vacuuming when using one of these. Just a suggestion.

Googles...... Now, it is true that under gravel filters do not provide high-quality mechanical filtration, and that the use of the carbon or resin inserts for the lift tubes will only provide short-term chemical filtration and will greatly reduce the flow through the system, thereby reducing the effectiveness of the filter overall... ' With canister you need put small hole under water level in connection to ugf, break syphon just incase as will empty tank. Does tick a few boxes, mostly out of sight not much tubing wiring easy to use. Great filter. Back in the day it was plants don't like fast water running through roots. Thank 4 vid.

So glad to see you changed your mind on UGF's. You really need to remove that other video saying that they suck. I still am amazed my local fish stores don't stock these anymore. They are pushing me to order from Amazon when I want to give them my business. Good explanation of why the UGF ROCKS.

It’s hard to beat I use Fx6 & Fx4 on my 100g connected to under-gavel filter an flush them out once a year with minimal upkeep makes life easy!!!

I am loving these A Tale of Two Cities series!!! It was the best of filters, it was the worst of filters!!! ❤❤❤

I will always use these in my planted tanks. The plants LOVE it!!!

Great video. Thanks! I've got a 55 running with a custom (PVC) UGF with two power heads. I did opt for schedule 80 (grey) PVC for the uplift tubes to make it less conspicuous. It has been bullet proof (and has not needed any cleaning/vacuuming of the gravel).

I just got back into this hobby and have been looking for a quality UGF. Thank you for the great video.

I have used them in combo with canisters filter. Saved my butt so many times. You have power outage you can but battery bubbler on underground filter. It also is a great piece of mind and keeps tank clean.

I really like this series a lot.

I run undergravel filters in an anoxic set-up. I have 10 diffrent tanks with them all set and working. Cloth on the plate with the red seachem and saftysorb on top. Takes a few months for the bacteria to set up. But once its set I only need to do water changes. And its hard to crash the system. The air pumps go out from time to time. Or an air stone needs to be switched out to get the flow back up to par. Otherwise its super low maintence.

I used these on two 20 gallon extra high tanks set up in my children's rooms. I powered them with Whisper 2's . The siphon tube with a small piece of clear vinyl tubing would make a perfect fit in the uplift tube. The filter medium and bags would only need to be changed every couple of months. I used a gravel siphon when I did water changes and that would clear out the mulm from under the plate. I could watch it from underneath. This setup was as close as I could get to a maintenance free tank. Thanks for the video.

Back in the 90s when I was a kid I had a 25 gallon tank with a filter like this one connected to a canister filter, 4 years without water changes or siphoning and no fish died, all I used to do was toping the water after evaporation and clean the canister filter once every 4 or 6 months. I had 2 or 3 generations of some fish in that tank and could have survived for longer but my heater malfunctioned one night and it boiled all my fish. Water was super hot even the plants died. That was my real fear, heaters exploding or malfunctioning.

I worked this out and looked for a video to support my plan, this is it. I will be trying it with my next tank.

I think the main thing people go wrong with under gravel filters is the flow. Too fast and you build nitrates. And too slow it doesn’t do much of anything. Get it right and you can actually reduce nitrates when anoxic. Dr Novak talks about it all the time but has been around forever especially in the pond scene with bcb which basically do the same thing. If you have a plenum and bcb canister or sump and can basically kiss your nitrates and phosphates goodbye. Fun stuff

Been in this lifestyle for just over a year. I've already had internal filters break on me. I got a tank, from a charity shop, I already had an air pump. For cost, I thought of sponge filter, but decided to go with undergravel. I had a small piece of filter floss, that covered one gravel plate, but I had two plates to cover. I split the filter floss, making it half as thick, so a very thin layer of floss. A layer of gravel on top, and a layer of sand to cap. One thing I noticed immediately is instant clear water. I put in sand, which always made the water cloudy, but within an hour, being honest half an hour, water was crystal clear. I have a larger 140 litre, seriously thinking of stripping it down and doing undergravel. Plus, can run both tanks from one air pump. Undergravel covers the filter, the surface agitation, oxygenation, all in one. Far as I can see, regular water changes all that's needed. I already had a weekly 10% change routine anyway. Now no cleaning of filter needed. I think it's the way forward

We had a couple of UGF aquariums in the 1970s and we had great performance and little maintenance. We found that plants did quite well in the gravel. That being said, I prefer HOB or canister filters because I like aqua scaped aquarium. UGF requires more or less uniform bed of gravel. All filters work and it boils down to personal choice.

Thanks to my Grandads advice, i am running an undergravel filter with a pat mini on top of the outflow pipe. The best thing I ever did. I set the filter up with the seachem matrix underneath the plate. I then covered the plate with a fine netting. On top of that, I used a mixture of Flora seachem nutra base and pond soil. I then used pea gravel and capped all that with sand. The plants are growing out of my tank and look amazing. It's been set up for 6 months, and all I have to do is water top ups with no big water changes. Old school always works the best 😂

Yes I too have come the the same concllusion that they work extremely well except when your fish dig like crazy or you want plants everywhere on the floor of your aquarium.

I worked in a shop for a long time that had a lot of tanks from 15-55g that all ran on under gravel filters (some running for over 25 years). All the tanks were drilled on the bottom and we did weekly water changes using those drains, which pulled out a lot of waste. We also gravel-vacuumed about once a month. We never had ammonia issues, even with rapidly changing stock levels.

Bentley, I am really enjoying this series you are putting out. I remember the UGF with the little filters on the tubes. I knew a lot of people who had them little filters. I think they had carbon in them. I have never personally tried a UGF and from what is have heard are outdated and don’t work that good. Hmm but if everything goes into the bottom wouldn’t they work better than the filters and HOBs that suck the stuff out of the water but can’t go all the way to the bottom. This would if setup correctly would essentially filter better 🤔 mind blown right now. Thanks brother. ❤😊

I've been using the same UGF for 40 years, I've only seen it once since it was installed. There are several benefits to using powerheads instead of air driven. The biggest for me is that I can prove how much water is passing through the filter. After moving the two 75s, the water was dark and muddy looking. The HOB tank cleared in about 2 days. The UGF tank was clear in 2 hours!

I have run under gravels with a HOB as the lift for the UDG. it work realy well. yopu get the benavits of both with one power draw..

Thank you for this video. I’m subscribing off of this video information. I’m going to try this with an AIO tank that I have. I think it’ll be a great planted system.

Hello Bentley, part 2,,,I mention that I would never remove the plate from the gravel to clean under it ,,,I would stick the siphon hose in the tube and out came the muck,,,also there was a power head the reverse the flow ,,but that would make a mess in the water,,,so not good I also put ehiem substrat pro media in mesh bags under the plate, so yes your on piont with the under ground filter,,I 55yrs old and my mom always had a tank in the home ,,,metal frame lol,once I got my first job I got a 55 gallon and now a 125 gallon tank ,,love it ,I also enjoy learning new things, I learn so much from you ,alex from fishtory,,father fish ,Dr novac, on utube, etc you guys make fish keeping easier,,not laziness, lol,,and better ways of keeping tanks the right way,,healthier etc,thanks for sharing your experience,,knowledge with others,your fan mg, see you on the next video

You my friend are outstanding, God has certainly given you a talent for this topic. I wanted to know if you can use pool filter sand with an U.G. filtering system. I have a small 10 gallon tank, with sand as a substrate. But my bubbler is causing way too much splash on the lid. Which is why i once went to an under gravel filter 7 yrs ago. Thxs.

You know if you slow down the airflow on your under gravel filter to maybe pushing only about 20 gallons or less an hour the anoxic conditions will reduce the nitrates to nitrogen gas N2 which will gas out of the water, which means you’re removing your nitrates, which means you will have no more issues with nitrate buildup. That is why it is better to create anoxic slow flow oxygen through the Plenum the denitrifying bacteria will eliminate or should say reduce the need for water changes by gassing off nitrogen out of the system.

I ha to watch both videos twice to get your message - I was unaware (at first) of the concept! Thanks Bentley!

I agree with you on it's great to get a good start with root feeder plants that's why my java ferns have grown so good including my red 1's, the only thing I didn't think about was covering the plates with something . But like I said in your other video I'll be changing mine around for a better outcome when I can get the chance which will be a little bit.

Great , now I want to start another tank lol

I love under gravel filters. They are simple, cheap, the entire gravel bed biologically filters the water, circulation is perfect and the water is well oxygenated. My only hang up is lack of access to the dirt under the gravel plate, but if you have a planted aquarium the plants will extend roots under the plate and feed on it.

I started with ugf's in the 80's then later went to hmf's next tank I'm setting up will be UGF but will add the pond fabric and some media below. Am thinking that kitty litter with a sand cap will be the substrate. Crypts and Anubias will likely be the plantings. Already have most everything I need including a cool piece of wood but had lacked the vision of how I wanted it to look. Got that cleared up by your video, so thank you for that!

Super video. I have really enjoyed this series of videos. I literally run most of the filters on the market in my fishroom. They all work just make sure you use the right filtration for the right application. Although i must admit that anytime i can get away with using a UGF i do. It's really my favorite method to filter my aquariums. Thank you, Bentley, for these awesome videos.

I remember using these in the 80's. I had one tank that had an eel that lived in the UGF and I didn't know it. He would come out at night and eat my fish lol. I put a few baby eels that I had caught in there and this one eel ended up 12" long before I noticed he was in there.

I found adding a layer of 1/4in sponge on top and cover with about 3/4-1in of substrate like Ada, etc. My tanks. I also toss a a thin layer of lava rocks

UGF has always been my favorite method. I've used HOB, power heads and just air. Most recently, I have experimented with combining OG UGF and Asian UGF boxes. I totally agree ... do what works for you but don't just think of UGF as low tech ... it's actually very good. Same goes for OG box filters. There's much to be said about "keeping it shrimple" ... lol.

The substrate filter is the best filter. Especially when running in conjunction with a cascade filter, air stone, and live plants.

Such a great idea for a series. Personally I love filtration discussions.

They are actually the best I’ve used and I tried them all, especially when u have goldfish , high bio load , under gravel def out competes, I think they couldn’t make more money off them, once set up they last for years . 💭🧐

I still use an undergravel filter in my larger tanks that I don't use for fry raising or breeding parents. I make them them out of 1/4 to 1/2" PVC and use powerheads, and they work amazing. Since I drill hoes in the pipe they're a non-plenum design, and they're only purpose is to drag water with waste into the gravel, where bacteria can break it down. But since I use a very, powerful powerhead, that's all it needs to do. Granted I always use a secondary filter alongside them, like an Eheim cannister or a deluxe Seachem HOB filter. However, the added benefit of the undergravel is a much lower nitrate buildup in my tanks, and much healthier fish. It's rare that I ever lose a fish with that system. 6:48

I kept a 4 feet plant tank in good condition since 1995 to 2020 with under gravel filter and a simple overhead filter with minimum maintenance . I change my tank after it start to leak. So far it is easiest plant tank I have. 😁😁

I had no idea you could use aqua soil w/ under gravel filters. Mind blown! I thought you had to use a ton of old school gravel. 😯

I had never thought to put media under the UGF. I will the next time i tear down and rebuild a tank. I do how ever put a layer of larger gravel - natural stone first then normal gravel on top and as you know I have hooked up my ugf to my over the back filter. Rooted plants love this.

I have a 75g with a thick layer of gravel. The Dwarf Sag has run rampant all over the tank. HOWEVER, the roots don't intrude under the filter plate. There is no nutrients they want down there. They are attracted to the upper layers that have a high ion exchange potential. and No root tabs needed, fertilize the water and the UGF does the rest.

My first tank in the seventies had a under gravel filter. When you started talking about how they sucked my head almost did multiple three sixties and and exploded. Then I realized what you were up to. LoL. Hey didn't the movie exorcist come out about then as well. Went to a neighbor kids house to watch it. I laughed at that movie.😂

Great video! Subscribed for the amount of information provided. Would love to see you make a video on a tank setup with the under gravel filter. I'm looking to get into the hobby and I will eventually, but right now I'm just gathering as much information as possible for my setup. Initially I planned on running a canister filter with a sponge filter. But after researching under gavel filters, I figured (technology science background) if I combine the under gravel filter with a canister filter on one side and add a power head to the other side the circulation of flow and bacteria hosed in the gravel itself would be massive. That was before I watched this video and you mentioned Master Dean uses a similar modern tech canister filter combined with under gravel filter setup. Thank you.

We used ugf back in the 70s and 80s. They work great. If you have gravel, why not use it to the max. All that surface area for beneficial bacteria with oxygenated water passing through it. I plan on using ug filters on my big tank and cleaning them once and a while with a shop vac. That will be way faster than vacuuming the gravel with a siphon.

Hmeonthelake I agree having an aquarium store with over 100 tanks all with UG. filters . I think are the best also least expensive and less problems. Canister and even hang on the filters cost more and can leak. U.G. is the best.

Love this series, Bentley! It demonstrates how our hobby has so many choices and we can all do things differently and be successful. Thanks!!!!