Water Change

i read many different opinions on how much water i should change.
10% weekly? 10% bi-weekly? 10% every 2 weeks? 20% every 2 weeks?
i'm confused. as for now i'm doing a 10% weekly.

i have a 55 gallon (soon to be) reef tank. about 75lb of LR. 40lb of LS. 2 diamond gobies, 1 percula, feather duster, bunch of snails (turbo and nassarius), 1 lawnmower blenny and 2 emerald crabs.

 

If you're doing 10%, you should be able to do it every other week if it keeps your nitrates down. I mean, that's really the big criteria; are your parameters stable while you do things that way? Some people don't do water changes after a while, leaving it past 6+ months, once their tank is a well-established, full ecosystem.

 

my parameters are stable...someone at the my LFS store told me that corals (that i will eventually have) like the water to be a little dirty.
so, do you think i should try every other week?

 

5-10 ppm nitrates are fine for most corals, sps,lps,softies.. so you'll just have to wait two weeks after a wc to test water. then do a 10% wc and test again next day to see how it affects your tank with your current bioload. more fishes,more feedings,etc all effect levels..

 

"A little dirty" usually means under 10 nitrates, 0 nitrites, 0 ammonia, <=0.1 phosphates, calcium > = 400, alkalinity > = 2.6meq, magnesium > = 1250, SG 1.023-1.026 if you're talking LPS (my LFS used the same exact phrasing to describe LPS requirements lol). Whatever keeps your parameters stable there should be good. Find out what your tank will handle, and take it from there.

 

I have a 55 gal. with primarily all soft coral (2 LPS) and I change 5 gal. once a month.
I think it depends on your filtering capability.

 

thank you! i think i'm gonna try 10% every other week and see how it affects my parameters.

 

I always do 10% every week. But that’s just me.

 

Man I've been doing 10% weekly in my 55 gallon reef tank... now I won't feel guilty if its been 8 days

 

I'd say it really depends on a few factors including your nitrate level on when to do wc. for nutrient export the larger % water change the better, lower % wc are not good for keeping nitrates at bay. so if you are having nitrate issues or a heavy bio load 10% weekly may not cut it. rather think about doing 25% every 2~4 weeks. if your goal, however, in a water change is to replenish trace elements than the 10% weekly is the best approach. in this event you want to be using a salt that states it has all the needed trace elements need to maintain a reef (not IO). in any event, If you have a cal reactor or are using a dosing system everyday you should not need to do the 10% weekly change regardless of your reef needs as you already are implementing a supplement regime.
Overall, If nitrate removal is the goal of your water change then less frequent, higher % wc is what you want to do. have a good skimmer and a fuge will allow your tank to remain nitrate free between wc as they should be removing nitrate continuously.