Let's talk about water change frequency

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fort384

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For the past 8 months of having my reef tank setup, I have been doing a 10-15% PWC once a week on my tank. This was mostly to keep Ca and Alk up as I wasn't dosing.

Now I have added a 2 part autodoser, and my test results are in the optimal ranges across the board...

0 NO3, 0 PO4, 420 Ca, 10dKH...

This is before doing my weekly water change this week... so can I reduce my PWC frequency now that things seem stable? What do you all do for water changes? How often? I realize that replenishing some trace elements is also important, but if I can reduce the water changes (and save myself time and money on salt mix) I would love to.
 
IMO I'd say you would be ok doing a 20-25% water change once a month, just watch your levels & see how much they change.
 
be very scarce with water changes

we think we know best, but the environment of a tank is very sensitive. even if the water is dirty, doing abrupt changes can kill all your fish. the best advice i ever got was to do a 25% water change evry 2 to 3 weeks...thats all. Remember that water changes very slowly in a tank giving your fish time to adjust. The quickest way to kill all your fish is to do a radical cleaning (and by radical I mean just 60%). Like everything in nature, it shouuld be done moderately, slow and steady.
 
It depends on what you have in your tank. Are you heavily stocked with fish and/or corals? Are your water parameters in check? Is it FOWLR? It also depends on how old your tank is, in my opinion. If it's a newer tank, then of course you'll need to do more water changes, but if you have a tank up and running for 8 to 10 years or more, you have a miniature ecosystem in place and may not need to do as many water changes. For example, if your chaeto in the sump is working FOR you.

I used to do 20% every two weeks, but lately, I've been doing a 20% change once a month. I'll keep that schedule up until my parameters tell me otherwise...
 
Following this one. I do 30 gallon pwc a week in my 180 fowlr tank . Stock is a porc puffer, emperor angel, whitecheek tang and a naso tang. Tbh I'm not really sure what would happen if I skip a week or 2.
 
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