Water Changes

[fish_4_life]

Hi All.
 
Question about water changes I do a 25% water change each week, Is that a normal amount?, My main question though is I replace the water out of the hose, I treat it with dechlorinater but put it in cold is this harmful to the fish? as someone told me recently it could be?
 
Thanks 
 
Dan

 

[fluttermoth]

I've been doing water changes the same way, on all my large tanks, for a few years now with no problems.

You must run the new water in slowly though, so as not to shock the fish, and you should add enough dechlor for the whole tank's volume, not just the new water, as some gets bound up in the tank.

 

[levahe]

25% Is a good amount, you can do more if you want. Some people do 50% it varies but the main thing is getting fresh water into the tank on a regular basis.

 

[wrightt3]

25% per week is usually enough but there are some things to consider such as how heavily stocked you are and what type of fish you have.
What is your stock list and tank size?

 

[N0body Of The Goat]

http/linuxhost.matsp.co.uk/calculator/
 
Post figures into calculator 1 to get an idea of typical nitrate level increases per week, then use that figure in calculator 3 to see what different % water changes will do.
 
I found that my 6-footer containing my biggest fish (a 22cm SL Synodontis notata and a ~20cm SL Giraffe Catfish) needs ~65% weekly water changes to keep the nitrates at a baseline of 60ppm, with ~40ppm coming out of the tap. I thought I was being generous with 50% weekly changes, every month or so doing one change closer to ~75%, but over a period of months the nitrate levels would still climb and could eventually lead to nitrate poisoning.