Under gravel filter - how much gravel?

[rcgldr]

I have a 55 gallon tank, with an under gravel filter setup as well as a cannister filter (eheim ecco 2234). I have 2 aqua clear 50 gallon per hour power heads pumping water out from under the under gravel filter.

The plastic trays for the under gravel filter sit about 1/2 off the bottom of the tank and I currently have about 1 inch of gravel above the trays. Is this too much gravel for proper circulation? I can scoop out some gravel and use a syphon / cleaner during a partial water change to redistibute the gravel without stirring up debris inside the tank if I need to remove some gravel.

 

[LyndaB]

I can't help with the amount of gravel, I'm afraid. From what I've heard, undergravel filters have a really bad reputation. I didn't know they even sold them anymore.

 

[Bubble_B0y]

I recommend 1-2 inches.
Any deeper and the flow through the gravel becomes less efficient. I recommend a powerhead attached to your undergravel filter.

Aquaclear Powerhead 50 and 70, are powerful and have a reverse flow fuction.

 

[Bubble_B0y]

From what I've heard, undergravel filters have a really bad reputation. I didn't know they even sold them anymore.

I feel undergravel filters do poorly alone.
But when coupled with a HOB filter, they are very effective.

 

[LyndaB]

Interesting, thanks for sharing.

 

[Fishguy2727]

I wouldn't do an UGF on any tank. They are problems long term. There are better forms of filtration these days.

 

[Batt4Christ]

I'm no fan of undergravel filters. Too much trouble in the long term, and don't do a particularly good job.

Years ago, I swapped a 30g with an UG filter and did a "reverse-flow" setup. Basically a standard powerhead pulling through a foam sleeve, pumping into the UG filter. It did somewhat better, but I had to use my canister to "suck" out a thick slime from the lift tubes.

But if you feel you must use an UG filter, I found that it took a minimum of 2 inches, and I generally preferred 2.5". Less pulled too much crud under the plates.

But I'm with others- no UG and a good hang-on-back is far better and easier to maintain.

 

[glassbird]

Whatever depth you go with, get bigger powerheads on there first! I like UGFs, if run with a HOB, but have always found that they need good strong powerheads to make them keep the underside of the plates clean. Powerheads that only pull 50 GPH are on the puny side!


Edited to add: 50 GPH powerheads would be really underpowered, not sure they even make them...did you mean 500 GPH? If so, two of those would be the smallest amount of "pull power" that might do the job on a 55 gallon tank (IMO). I would definetely not go any smaller than that.

 

[jpchin]

JUST WANTED TO SHOW MY UGF ON MY AQUARIUM. IT'S MADE FROM PVC PIPE THAT HAS HOLES ON THE BOTTOM TO PULL THE WATER THROUGH THE GRAVEL. IT HAS 2 POWER HEADS THAT PULL THE WATER THROUGH. THERE ISN'T ANY TRAY ON THE BOTTOM OF THE AQUARIUM TO GATHER GUNK UNDER AND I CAN RUN MY CLEANING WAND IN-BETWEEN THE PIPES TO THOROUGHLY CLEAN THE GRAVEL. I ALSO LIKE HOW MUCH GRAVEL I HAVE FOR BB TO GROW ON BECAUSE OF THE LENGHT OF THE TANK (56") THIS UGF WORKS GREAT AND I'M SURE IT WOULD BE EASY TO BUILD FOR SOMEONE THAT HAS O BIT OF KNOWLEDGE OF THE UGF.

 

[Bubble_B0y]

????
i've never seen an undergravel filter like that before.


Is that a coffee table Aquarium?
They are such gimmicks (like the picture frame aquarium), and function poorly as proper tanks.

 

[Dale_I]

Properly done, UG filters are fine. I'm old and "back in the day" it was the filtration of choice. I've run anywhere from 50 gallon to 250 gallon aquariums with them (alone) and have been succesful. However, you will need to clean the gravel from waste and excess food once every month or two.

That said, the pvc tube build isn't an Under Gravel filter. You need plates that allow for equal suction across the substrate to properly get bacteria to handle the chemical filtration.

What that looks like is a water cycler. They are made for fish that originate in streams and like a consistant flow of water all the time. It will basically take water in and then you can use power heads to create the flow in a specific direction.

Normally, you would shoot for a 2 to 2.5 inch substrate with 4 to 6 times your tank volume to size your power heads. The less your turnover rate, the less the substrate you should use. But, you don't want too little substrate or your bacteria don't have a good place to call home.

You will find that many forums poo-poo UG filters. Mostly due to inexperience, repeating what others have said, or poorly executed set ups. It is true that other biological filters can be more efficient, but there is nothing inherently "wrong" with properly set up and maintained UG filters.

Currently, I have a 55 gal corner bowfront with a Fluval 304 and an UG filter utilizing two 200 gallon powerheads. For my set up, I used just under 3 inches of gravel, but I have 8 times the turnover rate and can utilize more substrate.

My recommendation would be to get 2 inches of substrate and trade the 50 gallon powerheads for 100 or 150 gallon units minimum. That said, if you have the Aqua Clear 50 Power Head, that is a 270 gallon per hour rated pump. Two of those will do you just fine, but I would add more substrate than 1 inch. Probably 2 to 2.5 inches minimum for that turnover rate.

 

[rcgldr]

That said, if you have the Aqua Clear 50 Power Head, that is a 270 gallon per hour rated pump. Two of those will do you just fine ...

Yes, they are Aqua Clear 50's. You're correct they are 270 gph each. I thought the 50 meant 50 gph, not the recommended tank size of 50 gallons. The flow out of the nozzles, is like having two small garden hoses in the tank, which the fish sometimes likes to swim in.

I mentioned the fish in another thread here. It's 17 years old and I think it's a clown loach, but it's only 5 inches long, which is small for a clown loach. My wife wanted to get rid of the aquarium years ago, so we stopped getting new fish, but this one fish has hung in there, although it's much less active than a year or so ago.

The eheim ecco 3324 cannister has chambers for biologicals, so my main concern about the gravel is avoding the slime that built up under the plastic trays (I recently cleaned up the tank to get rid of the slime). Would be nice if someone made some type of small hose that could be used to clean out that slime from under the trays using the ports that the power heads are normally connnected to.

 

[Demonknight]

I have found the amount of gravel is also based on the size of gravel, the larger the rock the more you need to work right.
As for cleaning out from under the filters I found that getting a small hose that fits inside the tube and doing pwc from there seemed to help a lot, just move it from tube to tube when my bucket was full.

 

[Dale_I]

You don't want to get rid of the slime. That's nature at work. I understand the human response to want everything clean, but you can't see it under the plate unless you are crawling under your tank and looking up. In fact, if you could see the "stuff" that is in your gravel, you would probably want to clean that too.

Just fight the response to slime and let nature take care of the issues that kill fish in an aseptic environment. You don't want everything sterile.

 

[Fishguy2727]

A biofilm of nitrifying bacteria is very different from debris rotting and polluting the tank.

IME the best substrate by far is sand. It is much more natural than gravel and is much cleaner. I believe that ten or fifteen years in the future people will look at gravel like they do with UGFs now, old school, out-dated, and not ideal, with a few people who have been using it since it was standard still holding out and making it work well enough.

 

[jpchin]

????
i've never seen an undergravel filter like that before.


Is that a coffee table Aquarium?
They are such gimmicks (like the picture frame aquarium), and function poorly as proper tanks.

why do you assume that the coffee table aquarium is not a proper enviorment for fish? what's wrong with it? it has a great deal of open space and length(56") for the fish to swim freely. all my fish are suitable for the dimensions of the tank. i have a great filter system and ALL my water parameters are spot on. i am not over stocked and i haven't had one(1) fish die since the aquarium has been set up. (going on 9 months) i have 2 german blue rams that are very healthy and their coloring is beautiful. i do ro water changes (15%) every 3 days. so tell me what's wrong with my aquarium? it's not the size of the aquarium or the style of the aquarium. it's how much effort you put into making it a hospitable environment and meeting the needs of the fish you choose. i feel i do a great job of that and i'm sick of hearing how a coffee table aquarium is paramount to fish torture. i think it's very narrow minded of you to dismiss the aquarium just because it's a different shape than most other aquariums.

 

[Fishguy2727]

Why are you using 100% RO water for water changes? That is not a good idea.

How many gallons is this tank?

 

[jpchin]

i use a mixture of ro and tap to get a ph of about 6.5 for the rams and the dwarf gourami's. why would all ro water be bad? just wondering because i don't have a lot of experience with ro. i have seachem trace minerals to add to the ro if i use more than 1/2 in mixture. any thoughts would be appreciated.

 

[jpchin]

i forgot to add it's 45 gals.

 

[Fishguy2727]

All RO means there is nothing in the water, no ability to hold a stable pH, nothing. Which Seachem product exactly?