How often and how much water to change?

[thakki]

I have been following a routine of changing 15% of water every week...is it too stressful for the fish?

[Ryan S]

I do 10% per week.  Many do 20% every 2 weeks.  Randy Holmes recommends 30% / month.

 

It's less stressful to the fish if you can complete the water change in the sump, versus in the DT, or if you do it at night when they're sleeping already, versus during the day.

[Bruleyii]

My clowns don't seem to care. They like to dance in the water being siphoned in.

[sen5241b]

Lazily wait 3 or 4 months then dose make up water with cal and mag till it almost precipitates then do a 50%. Cal and mag stay good with no dosing necessary for at least 8 weeks.

 

Understand that 5 10% changes is NOT the same as one 50% change. I've heard recently of people doing 90% changes and their tanks are fine.

Edited December 14, 2014 by sen5241b

[Ryan S]

http://reefkeeping.com/issues/2005-10/rhf/

[zygote2k]

I personally maintain 60 aquariums. The ones that get weekly water changes do the best followed by the ones that get serviced every two weeks , then the tanks that get monthly service.

I routinely do 25g w/c on tanks as small as 60 gallons and do 100g w/c on a 375 and do 300g w/c on a 600g pond.

On my own system I do a 15g w/c on a 150g system.         

[TrueTricia]

I think it also depends on your water paramaters. If you have a newer system that isn't as stable, weekly water changes might keep your nitrate and phosphates down. If you have an older established system that seems to be pretty stable, then water changes every 2 weeks may be just fine. So if after doing a water change on Monday, your nitrates are back up again on Sunday, then the weekly water change may be the way to go. If your tank parameters haven't moved by Sunday, then you could probably wait a week.

 

Personally, I do weekly water changes, but my volume changes. Sometimes it's 40g for a 140g system, sometimes, it's 15 gallons. It depends on how much water I've managed to make for the week and how my water params are doing.

[gmerek2]

I do 15 gal weekly on a 125 Every Water change Wednesday. I feel that less water more often keep parameters stable. But I also agree that a newer system May need more volume

[lnevo]

On my own system I do a 15g w/c on a 150g system.         

 

At what frequency?