Do I need more filtration?

Question
Karen, I just setup a 75 gal two weeks ago and have a canister filter (80 gal cap). My water is still cloudy and just noticed ick last night. I'm treating the ick and also put in melafix. I have six fish in it. Two Oscars (4 & 7 inches), one silver dollar (4"), a Dempsy, a Convict and a Pleco (each about 3"). Over populated??? Should I put in an under gravel? And can I put that in while the fish are in it? Or am I being impatient? Do I start water change now? Even though it hasn't turned? Help, I don't wanna loose my Oscars.

Answer
Hi Felix,
Oh you have a scary situation on your hands.

With the tank being a new setup, the fish being big polluters and the tank not having any time to be cycled.

If you are unsure what cycling is. It basically means allowing your tank time to develop special beneficial bacteria that convert ammonia produced by the fish over to less dangerous chemicals. They do this in two steps. 1.) Bacteria develop and convert ammonia into "Nitrite" which is still just as dangerous as ammonia to the fish. 2.) More bacteria develop to convert "Nitrite" into "Nitrate" which is safe and is kept in check with your usual maintenance water changes.

*You can test for all three levels- ammonia, nitrite, and nitrate with simple easy test kits from your petstore.*

But aquariums take 6 weeks or more to fully cycle. And stocking a tank too soon with too many fish can almost guarantee deadly ammonia buildup, cloudy water and some very stressed and/or diseased fish. The ways to avoid this are stocking your tank with only a few small hardy fish and waiting until the tank's levels (ammonia, nitrite, nitrate) are at a safe range to begin building up the tank's population gradually.

What to do now???

Do your best to battle the current situation.

It doesn't hurt to do partial water changes every day even on a tank that is cycling. I feel your fish need this especially since we have no idea what the tank's levels are currently at. I would change about 30% or more everyday until you can be sure the water is safe. (try to get test kits)

Ich treatment is relatively straightforward and easy to do but you must catch it as early as you can. You'll need-

*Quick cure ich medication (or a similar ich medication)
*Aquarium salt (optional... good for deterring parasites)
----------------------------

Treatment:
*Raise the tank temp gradually over a few hours to 83-85 degrees
*Make sure aeration is going at its best (no clogged filters and plenty of surface agitation)
*Do a 50% water change
*Add quick cure (or other ich med)
*Add aquarium salt (again--optional... make sure to predissolve it first in a cup of water and add small amounts over a few hours)

~Treat for minimum 12-14 days. This is against most medication directions but it is VITAL that you continue treatment even when the ich spots disappear because they have a long lifecycle and a sudden disappearance can only be due to part of their 'multiplying stage'.

During ich treament, water quality issues are very likely. So I would try to do water changes every day on this aquarium during treatment. Or at least every-other day. Simply redose the medication and add back only enough salt according to however much water you took out.

By the way, just leave out the Melafix. It really does no good for your fish and is only really helpful for helping out nipped fins or minor scratches. Clean water does more than melafix.

Also, an undergravel filter would not be a good idea for a tank setup like this. Canisters or Hang on the back Power filters are much better for big polluting fish like you have. Undergravel filters aren't suitable for very many tank setups due to their tendency to trap waste beneath the plate.

Best of luck and I hope this helps!
Karen~