Can you over filter?

[mr.wen]

Well for my grow out tank (55gal) I will use the sponge filter. But when I move them to the 75 gal will this be over kill? One Penguin 350 Bio wheel and a fluval 305 and maybe a sponge so i can move that to the HT or QT when need. What do you guys and gals think? I also have another bio wheel on hand if needed.

[Lenin]

No such thing as overfiltering, you do have to take into account water movement, discus do not like strong currents.

[strawberryblonde]

I don't think there's any way you can overfilter, but at some point the law of diminishing returns kicks in and at that point it no longer makes sense to add more filtration.

Basically the mechanical filtration removes the big cruddy particulates, and should be rinsed out regularly so that the crud doesn't decay in the tank/filter.

The biological filtration will only produce enough beneficial bacteria to handle your bio-load and will not make more than that. Since it's a living organism, it must have sufficient food (ammonia or nitrites) to live. Each fish will produce a certain amount of food for the BB and food and fish wastes will provide another source. Add those two together and that will pre-determine how much BB will grow in your filters. So long as you have enough bio-material for the growth and maintenance of the beneficial bacteria you're fine. Any more than that is just a waste of space and costs you money to install it so it can sit there and do nothing.

You also have to consider electricity to run bigger or more filters. Why spend that money on something you don't need, when you could be spending it on more fish! =)

Discus do like softer currents than most other tropical fish and they love plenty of good aeration. For that reason I've chosen to run a double stacked sponge filter on one end of my tank and a HOB filter on the other end. I don't even have mechanical filtration to speak of since I clean and change water nearly every day. I'm also careful not to overfeed so there's no accumulation of food sitting around.