water changes

[st3]

i have a 90 gallon tank and have a few fish. how often should i change the water and how much.i used to change 10-15% a month but people told me to do more.so i did a 25 % change and my shrimp died and anemones turned white.

 

[yosemite sam]

10%-15% every month is the "text book" answer, and I think many people on the board more or less follow this. That seems odd that a 25% change would put your tank under that much stress (sounds like your anemones bleached). Do you use RO/DI water or normal tap water? Was there a big change in the salinity?

 

[nicky1.8t]

i havent done a water change in 5 months and everything is going strong. i am goin to upgrade my tank in a few weeks so ill need to and some new water and some new salt

 

[nm reef]

I prefer to do 5-10 gal water changes monthly...my water volume is about 100 gal total so for me 5%-10% monthly works fine. There are several ideas on doing water changes...I like to think its a good way to remove old water and potential toxins and at the same time it replenishes trace elements. But it is a good idea to insure a quality water source is used and insure the water levels(temp/PH/specific gravity) closely match the water in your display.:thinking:

 

[st3]

thanks

 

[jacksonpt]

I think it has a lot to do with what your water params/livestock say. I went about 6 months without doing any water changes on either of my tanks... all I did was topoff water lost to evaporation. One tank still hasn't seen a water change (going on a year now), while my other tank has been needing water changes every week. I definitely think that my 1year no water changes is not the norm, but I don't think weekly water changes are necessary either, generally speaking.
If you want to do water changes, I'm a firm believe in more frequent water changes with less water (i.e. 5% water changes every 2 weeks) as opposed to infrequent water changes with more water (20% water changes every 2 months). I would say to start with 5% water changes once a month. If your critters are happy with that... stick with it. Don't change just because the board/your LFS/whoever says so... we don't see your tank every day. You know better than us if your critters are happy - if they are, keep with what's working. If not, try something different.
HTH.

 

[lm]

I have not done a water change in 3 months and all readings are perfect and everybody is doing great (I do add top off water everyday though). I too have the question should I do a water change or continue what is working??

 

[skooby]

I do a 5 gal water change in my 55 everyother week, and I do a 10 gal water change in my 75 every other week. I set up a constant RO system so It makes me do this often. My tanks look awesome.