upgraded Fluval AC20 Power Filter

[bgarthe]

Looks good. Love the foam baffle…..I use similar type baffles to slow /disperse water speed some too. You might find cleaning the AC later on easier if you enclose your ceramic media in the mesh media bags. Then, when you lift up the foams and ceramics to clean, the ceramic pieces won’t fall all over the place…..they’ll stay contained in the mesh bag. Just my thoughts.

 

[JCinPA]

I am looking for a flexible bag for that purpose. The bag that comes with the filter was supposed to stand up in the slots I cut away, and was not very flexible, which is why I discarded it. I'm sure I'll find a softer bag on Amazon shortly. Good idea.

 

[fishorama]

I have to weigh in on the UGF "debate". We had them in all tanks up to 55g driven by air stones & with HOBs for maybe 15+ years. We, of course, started with the corner box filters, then a big Supreme HOB that was hard to start due to the large diameter suction tubes (my thumbs were too small). Then on to UGFs w/HOB(s). At 1st they were great!...except for the fine "crap" that was lifted by the slow flow from air stones even though we gravel vacuumed regularly. Looking under the tank there was a lot of fine crud under the plates. We sometimes tried to feed airline tubing down the lift tubes to sort of clean down there. & yes, fish could & did get underneath the plates. Then we tried plants. OMG! Roots, even from anubias & java ferns, clogged the plates. I removed the last UGF 20+ years ago. What a mess that was!! & arguments with my UGF loving husband, lol

In a sort of defense of UGF, I'm sorry we didn't try powerhead driven 1's. Or even PH driven reverse UGF, where the flow goes down the lift tubes & "crud" is forced up through the plates to be removed by HOBs with fine media. I know saltwater folks still use UGF at least sometimes. They don't have plants & tanks are much more lightly stocked.

Your tank is quite small, maybe lightly stocked? How many years has it been set up? I'm guessing no live plants or very few. I'm glad UGF is working for you now...for this tank...but that's not my experience or anewbie's over long times. I'll not say never UGF again, but not in my foreseeable future

 

[gimme30]

In a sort of defense of UGF, I'm sorry we didn't try powerhead driven 1's.

I wonder if that has anything to do with why some don't like UGFs. Airstones, besides being maintenance intensive, can't provide near the same flow as a powerhead. I've only ever used powerheads but I can see the how the low flow of an air driven setup might result in clogs and excess waste under the plates.

 

[JCinPA]

FWIW, I’m an old-school user, and I go pretty much by what’s covered above in my deep dive link on these. I’ve never overstocked and aquarium, I’ve always used correctly sized gravel, I’ve always used air stones, no power heads, and I’ve always been light on the gravel vacuuming (1/4 of bottom each water change). I’ve never had a clog, never had any “dead spots”, had thriving live plants in my teenage years tank, and it ran like crazy for about 5 years.

When I hear about problems with them, I’ve noticed that often people are trying to run finer sand or even dirt over landscape screens, think they are “improving” them by reversing the flow, adding power heads, grossly overstocking with fish, etc.

These were designed for lower flow (airstones are surprisingly efficient, providing maybe 1-2 gallons per minute per lift tube), they were designed for use with about 2” of 3-4mm or larger gravel, and normal fish stocking levels. I’ve always had an oversized HOB filter as well, running both, and you can safely and slightly increase the fish bioload if you do this.

I hate words like never and always, but if your setup fits this description and you gravel vac only 1/4 of the floor each water change, I can practically guarantee you won’t ever have an issue with them. but under those specific conditions. My early tank ran for 5 years perfectly that way, never did anything to the gravel or UGF in that time.

All personal experience is anecdotal, of course, but millions and millions of fish keepers have had my experience with them over many decades. I think a lot of aquarists are inveterate tinkerers, and cause a lot of their own problems. We tend to complexify very simple things.

Use them, don’t use them, whatever floats your boat. But if you decide to run one, run it as described, don’t futz around with landscape cloth and dirt and such, use other methods.

I’m planning a 29 gallon tank now which will have two PennPlax undergravel plates, a sheet of fiberglass window bug screening (safer than landscape sheets, no possibility of chemicals), two inches of this 2-4 mm gravel

Amazon.com

And I will use an AC50 filter set up like the AC20 above. I expect the tank will run until I move or die without issue.

Link again for convenience.

8.5.1. Under-Gravels in Depth - Aquarium Science

A Caveat Undergravel filters have not been widely tested as a filter in the aquaculture industry, The limited testing done on gravel filters for aquaculture was "all over the map" due to the very high loading of commercial operations. So one is left with common sense and anecdotal "testing" as...

aquariumscience.org

 

[JCinPA]

I also think folks who do have problems with them may be in the either/or camp and are only using UGFs. I think an air powered UGF in conjunction with an oversized HOB filter is darn near foolproof. I’ve not run one alone. That would be part of my recommendation if you want to try one.

Airstones
Only gravel substrate, period!
Add an HOB

You should have glass-clear pristine water with that. Try it, you might like it. But no “fiddling”.

 

[TwoTankAmin]

I am a big fan of AquaClears. At my peak I had 28 of them running. I have every size they make. Often I have two on a tank, one at each end. I pretty much load them all the same way. Two pieces of foam with a semi-rigid floss pad cut to size between them. Initially I used the sponges from AC as the media, Then I discovered Poret and over they years as the lower quality AC foams degraded and needed to be replaced, they were but with 20 ppi Poret.

I find the 20 ppi to be the best compromise in terms of not clogging but also doing the job well. I use the 10 ppi foam for making my pre-filters. In a bigger filter or a sump system I would use a 10 ppi sheet followed by a 20 and then maybe a 30 as the final foam in the flow. TI Clogging is what can kill filtration as it prevents the water from delivering the needing things to the microorganisms doing the actual filtration work. I have had ATI foam compress to where the output almost died. This has never happened when using the Poret.

As always, this is my way of doing things and it has worked well for me. This does not mean it is necessarily the only or even the best way. Each of us must do what we thinks is the best way for what we want to be doing in our tanks.

I will offer one thing i have learned over my 78 years. "The best and cheapest solution in the long term is usually one that costs more up front."

 

[JCinPA]

I will offer one thing i have learned over my 78 years. "The best and cheapest solution in the long term is usually one that costs more up front."

Hahaha! This is almost a truism in everything in life. Buy once cry once. I had what was a nice filter in my ten gallon tank (Marina Slim S10) and a month later upgraded to the AC20. Then modified it with the foam stack. Oh well, live and learn.

I never had an older model, but my current model appears to have addressed all the issues. It's a bit less brittle. The media basket is locked down. The filter will prime itself after a power outage. I just love this thing.

I'm going to look into that Poret foam for my next tank setup. Sounds interesting.

 

[GaryE]

I run a number of homemade UG filters. I had good experiences with them back in the mists of time, and I wanted to experiment. They've been excellent.
I used to breed Satanoperca, a delicate enough fish, in third hand tanks I'd bought with UG filters of the type I make in them. I wanted to see if that was a fluke. It appears not - they work as well as one could hope.
But I'm the mistrustful sort, and never run one filter on a tank if I can run two, or on a large tank, three. Because I've run my tanks for many years, I've learned that even the best equipment breaks. And the worst equipment breaks quickly. I don't keep a supply of powerheads on hand if one breaks and shuts down my undergravel. My local stores are limited, and I have to online order replacements. I do have back up air pumps, and in my one air driven UG tank, 2 different filters under the gravel in one tank.

Plan B is usually useful, eventually. A lot of the gear I have here is all wearing out right about now. It happens.

With the right fish and plants, most filters work.

 

[JCinPA]

1. I'm a believer in the "one is none, and two is one" philosopy, which is why I never run a UGF alone, always in conjunction with a HOB filter. My next build will be a Seapora 38 gallon tank, with 3 UGF plates and lift tubes, and an AquaClear AC50 set up with my sponge stack. My next tank will have a sheet of inert, fiberglass window screening material over the plenum and use CaribSea's 1-2 mm Peace River gravel. Coupled with the AC50, should be a super clear tank.

2. @TwoTankAmin has repeatedly mentioned the Poret® foam so I decided to research it. Fortunately, the foam block I purchased is aquarium safe (chemically), as is the foam that comes with the filter. But for my next build I will buy some of that Poret® foam. It's spendy, but apparently it is much more durable than cheaper foams, and much more uniform. Sounds like a product that is worth the "buy once, cry once" treatment.

 

[JCinPA]

Final modification to the filter media. After learning about the superior biological capacity of 30 PPI foam over the ceramic stuff, I chucked the BioMax. I also chucked the 20 PPI foam in the bottom and got a second 30 PPI Fluval foam block. The FilterFirst dual-density pad was a bit floppy for my taste, so I got some AquaNeat 40 PPI 1/2" thick foam sheets and cut out a block of that. Now the flow is the pre-filter on the intake tube (20 PPI), two full 30 PPI foams and one 1/2" thick 40 PPI foam on top for polishing. I'm done with this, but I think this will be a real biological powerhouse in a couple weeks when the new foam is fully populated with bacteria and bio slime.

 

[gimme30]

The resemblance is uncanny!

It used to be a 'thing' to stuff these into a canister filter, straight from the dollar store at a fraction of the price of "aquarium" sponges. I like them because they're every bit as effective but don't restrict the flow as much.

 

[JCinPA]

I understand a lot of canister folks have replaced the expensive bio media with those and they work very well. Congrats on TOTM, gorgeous tank you entered!

 

[gimme30]

Thank you @JCinPA! A lot of people here are true artists when it comes to that sort of thing, I just got lucky.
Anyway I can't remember where I saw it but someone had done a study of various materials and their effectiveness in harboring beneficial bacteria and pot scrubbers were right up near the top. The ceramics didn't rate anywhere near as high, not that they don't work, but pound for pound they're unnecessarily pricey. A bag of plastic army men will do the same job.