Large water changes input

[waynemah]

Originally Posted by sirruckus

actually I haven't cleaned the canister filter - all sponge material etc. has been removed, only the ceramic balls are inside.

The Ceramic balls might be the cause of your nitrates... If you have room in your sump, you might want to consider sourcing a zeovit reactor, use the zeo media and go on the base system (Start, Bak, Food). It's a fairly proven system and well supported.

[Aquattro]

Not sure what the concern is on water changes. Where does this common 20% come from? Not sure how too much clean water is going to hurt your fish, given that the important parameters match.

[waynemah]

Originally Posted by Aquattro

Not sure what the concern is on water changes. Where does this common 20% come from? Not sure how too much clean water is going to hurt your fish, given that the important parameters match.

I threw 20% out there because It's what I've had experience with. Personally if it came down to it and fish were dying, I'd do as large of a water change as fast as possible. But I don't want to be responsible for crashing someones tank with inexperienced recommendations.

[Aquattro]

Originally Posted by waynemah

But I don't want to be responsible for crashing someones tank with inexperienced recommendations.

fair enough

Think of it like this..if you bought a fish or coral, and the water was pretty close to your tank, would you acclimate or just add to the tank? Personally, if I get a fish from a friend's tank and we're anywhere near close to temp (that's all I'd look at), I dump the fish in my tank. That effectively is a 100% water change for that fish. I've never lost one to new water. Same with corals. I float a bit to equalize temp, then in it goes. Completely different water than it came from = 100% water change.
The bacteria you want to filter your tank resides on the substrate. The amount free floating will have no impact, so that's not an issue.

I suppose one caveat might be that if your tank is so filthy and the fish have become accustomed to living in sewage, too much of a good thing might kill it. I doubt this is the case

[Proteus]

I do 50% WC all the time. Though not cost effective I enjoy doing it for fun. Ans as for coral above water I wouldn't worry. Most of mine are exposed and if I'm making frags they sit on table for 5 minutes

[marie]

I have done as close to 100% water change as you can get (if you don't count the water still trapped in the rocks) with no issues.
If my nitrates were that high I would change out as much water as I could

[sirruckus]

for those of you who have done such large water changes - what method do you use to pull the water out of the aquarium? and replace it?

a pump seems to be the best idea for something that you would probably want to get done fast rather than relying on siphons

Thanks for all the input