80 Percent Water Change

[Ady1397]

I just cleaned out my tank. Changed all the water and cleaned al the crud out off the bottom..

Im using the same two filters.
How long will it take for my tank to cycle again..

30 gal tank
too many fish

Is it bad to change all the water????

 

[Allivymar]

You will likely have a mini cycle, but as long as you kept the same filter media it likely won't be as severe as it could be otherwise; you'll need to test the water daily tho to be sure ammonia doesn't spike.

As for such a large water change, its not recommended unless there is a water problem (like a large ammonia spike). Even then, more then 50% is not a great idea as its difficult to match water temps and pH. Frequent smaller changes are a much better idea.

 

[tabitha]

its not a good idea to change all the water b/c this will kill all your bacteria (or most of it) and you will have to start over and cycle the tank again (4-6 weeks). do you have fish in it currently? b/c i would be careful when the tank cycles agian with your fish in it if you have them... i reccomend that you do a 20% change each day until the tank is cycled to keep your fish from becomming too stressed from changing water conditions...
hope that helped and good luck!!

 

[Allivymar]

Actually Tabitha, big water changes aren't such an issue when it comes to the nitrifying bacteria. They colonise surfaces and are found only in small numbers in the water column (is why using used tank water never seems to help cycle a tank, but using gravel or filter media from a mature tank does). The prob with big water changes is temp and especially pH. If pH isn't matched, it can shock and even kill the fish.

And again Ady, as tabitha and I mentioned, small frequent changes are better for the fish

 

[tkos]

Yes, I have recently found that my GH and KH are quite low. After a week there is a slight drop in pH as all the carbonates are being used up by plants. If I did a big change of more than 30% the pH would start to jump too high. So it has become more small changes to keep things stable for me.

As for all that crud in the bottom of the tank I suggest getting a gravel vacuum and getting that to suck up all of the crud without removing all of the water. Doing it with every water change will really help things.

 

[Ady1397]

Thanx everyone!!!