Currently in my 55gallon i have an aquaclear 500 runing ( 500gph ), i was thinking about adding a second 500 to the tank and staggering the intakes. I would be adding the filter for no other reason than for additional filtration. is this going to be filtration overkill, is there such a tthing as to much filtration. if i were to add the 2nd filter and had the intakes staggered would i need to switch there locaqtion occasionaly meaning if i am filtering lower on the right side and higher on the left shoud i switch them every week or two. to filter lower on the left and vise versa.

I would not be buying the filter it was given to me by somebody who no longer has her tank. so the filter is not no cost to me except fo rthe new filter media.

as long as your not creating an insane vortex where the goldies cannot eat and rest in peace i believe firmly that a goldie tank should have two filters. what about a canister?

honestly i have not even thought about a canister, probably since i dont know anything about them all. Maybe i should look into them i have heard only good things about from what i have read on the board here.

500 gph is enough for a 55 gallon for goldfish. However, do you know the actual gph you are getting after factoring in hose-length and heigth?

I would think you aren't under 300. In the case of 300gph, another filter would be good, but a second 500 gph may make it a little too unrestful or maybe just expensive overkill. Look at the chart for hoselength and maybe post your calculated actual GPH. We can make better suggestions from there

Chart for hose lenght.? Im lost, sorry. can you explain where this chart is and what hose am i loking at my intake tube. if we are talking about the intake tube it is maybe 10 inches long +/- a little.

There usually is a chart with the equipment. My powerhead has one, but I don't have a canister. The hoselength for moving the water upward into the tank is what takes about 200 gph off of the actual power of my powerhead. The same physics would apply to a canister.

In the instructions for your canister it should explain how hose length and the lift the canister must work to get the water back into your tank which would effect your gph. I assume the canister is beneath your tank. It may be running at 500 gph and it is already calculated. If so, 500 gph actual is putting you at about 10x filtration. That would be plenty.

It's not a canister, It's an Aqua Clear 500 Power Filter Hangs on the back of the tank.

Oh yes... sorry for the mix-up. :

Well, then you are at 500gph and that is about 10x so a lot more filtration factor wouldn't be necessary. Maybe an airstone or bubble wall to move stuff off the bottom.

The type of filtration is probably what you want to think about. Are you getting enough bio-filtration or mechanical? Are you getting a lot of gunk stuck on the bottom? I usually get that with a throrough vacuming every week. It depends on what you want to accomplish but the Aqua clear is giving you a lot of gph, so I personally wouldn't think you need so much of GPH as anything. My bio-filtration comes from a wet-dry filter, so I have plenty, but my GPH could be improved from the bottom of my tank. I, for example, could improve there. But I don't feel a need to just add GPH.

So, maybe that is just the answer. Your GPH is fine. Maybe we want to understand better about what you can accomplish with adding filtration. The aquaclear does have some biological filtration, which is good. I think moving gunk off the bottom could be improved upon. That's why I suggested a bubble wall or airstones. Or maybe a sponge filter on the bottom. There's a lot you could do, it depends on what you want to accomplish.

Oh yes. Some people like to have a backup filter in case one goes out. It still could be helpful to add a little more.

the only reason i was going to add the 2nd filter was for just that a 2nd filter. I already have a 48" bubble wall at teh back of the tank. I was just going to use the filter as a secondary filter is all. and wanted to know if there was such a thing as over filtering the water.
My parameteres are perfect, water is crystal clear aside from the bubbles you would not even know there was water in the tank it's that clear.

I see.

The only reason I can think of to have add a little more is for backup in case of failure. Otherwise, I don't think you want a 500gph due to the fish needing rest and you are already running the water at a good current already. It all depends on the sweet-spots you have. It's just my opinion, though. You are doing such a good job already, nothing really stands out to me that says "do more". Only putting a small filter extra, in case of failure, and when you come back from work with at least some filtration happening in that scenerio. But that's all I can think of.

Ok, makes sense to me. Maybe i will take the Aqua clear 300 off my 20gallon and put the 500 on that tank, and put the 300 on the 55 as a little added.

Last time I checked AquaClears 500's run about 300 gph. So in that case you could use another one.

IMO no such thing as too much filtration unless of course it blows your fish around

He's right. It runs at 500 gph:

http://www.petco.com/product_info.asp?webt...&sku=1556110620

Well they say ya learn something new everyday

I don't think there's such a thing as too much filtration either, as long as there's calm places for the fish to rest and they don't seem bothered by the extra current. I have a penguin 330 on my 20 gallon tank, and 2 penguin 330's and an eheim canister at 116 gph on my 50 gallon. My fish seem quite happy and aren't stressed at all by this amount of current.

I share the same opinion as valkyrie. But the effect of over filtration becomes more of a problem with thanks smaller than 20 gallon. I'm also at a turn around of 18X.

Thank you, everybody for your advise. i was away for the weekend and could not answer. I think i will go ahead and add the extra filter and see what happens.