Prophylactic treatment in qt

[dsfireman]

So I have been wonder a few things lately. If I understand everything I have read on Ich correctly I have a few questions related to keeping ich out of a tank.

1. If I have new fish and I place them in qt for 8 weeks, if I never see ich, how can I be sure they are not carrying this disease and bringing it into my once fallowed tank?

2. If I buy corals at a fish store, how can I be sure I am not bring ich in cysts on the bases/rocks of the coral pieces?

 

[HumbleFish]

1. If I have new fish and I place them in qt for 8 weeks, if I never see ich, how can I be sure they are not carrying this disease and bringing it into my once fallowed tank?

There are usually symptoms other than white spots, but they can easily be missed. For this reason it's best to just assume every fish you buy has Ich and treat in advance. Copper, tank transfer or one of the quine drugs should do it. Also, treat with Prazipro for worms either before or after Ich treatment. That should cover most of the bases.

2. If I buy corals at a fish store, how can I be sure I am not bring ich in cysts on the bases/rocks of the coral pieces?

IMO, this is tricky. I guess the only way to get close to 100% is to QT them in a fishless environment for 10 weeks. Same as going fallow. But that is a serious PITA. I've read opinions stating that 3 days isolated is sufficient and/or "washing away" cysts with tank water before placing in the DT works. I guess every little bit helps, but I can't completely wrap my mind around that logic.

 

[wooden_reefer]

You should assume that ALL fish are naturely in a state of light infestation as far as protozoans are concerned.

You should know that the closed system of an aquarium profoundly and utterly changes this parasite-host relationship.

So the first question answers itself.

The second question is that of human factor during transfer. Some ich in any lifecycle can be kicked into the bag that contains the inverts during transfer. The risk is likely less than with fish, but what chances are you willing to take?