Water change size and frequency

[dax123]

This topic has all all sorts of recommendations from frequent smaller water changes to monthly larger water changes. On a smaller tank it is fairly simple but I'd like feedback for a 120 gallon mixed reef.

I typically do 5 gallons a week or 10 gallons every two weeks because it is easier. Would it make more sense to do say 20 gallons monthly ? and why?

 

[reefergeorge]

It is whatever works best for you and your tank. If you like messing with it do weekly water changes. If not, monthly or less. The math shows there is little difference in effectiveness.

On my 125 I get the brutes out and do 60g whenever the tank starts to look dingy.

 

[hogfanreefer]

25 gallon change every 7 to10 days in a 155 for me.

 

[UTCReefer]

35 gallons once a month or so for my 180.

 

[jdpiii3]

5 gallon change daily, takes all of 5 minutes.

 

[dax123]

reefergeorge, How long does it typically take for your tank to look dingy?

hogfanreefer, assuming a 155 gallon tank has 130 gallons of water (live rock displacement), that's about a 20% change almost weekly. Seems excessive for a large tank. I'm sure you're parameters are spot on but any particular reason for your regimen?

 

[Spar]

5 gallon change daily, takes all of 5 minutes.

+1

equates to 1% daily

 

[djp2313]

10-12 gallons every 7-10 days on a 120
I aim for once a week but things get in the way.

 

[HowieB]

20 gallons every other week on a 120.

 

[Twistofer]

I watch my water parameters and have found that 20-25% change on a monthly basis works for me.

 

[reefergeorge]

reefergeorge, How long does it typically take for your tank to look dingy?

hogfanreefer, assuming a 155 gallon tank has 130 gallons of water (live rock displacement), that's about a 20% change almost weekly. Seems excessive for a large tank. I'm sure you're parameters are spot on but any particular reason for your regimen?

I usually don't like to give this advice, but it works for me. On my 125 I may do a water change every six months or so. It has probably been longer than that now. I check my kh and salinity every week or two (especially if the skimmer has been skimming wet), and check the others when I have the time. If everything is in check, I write it in the black book and move on.

When I started I did 10% a week, that changed to biweekly, then monthly, then whenever I get time. If my tank took to much time or money it would be gone, so I keep it simple.

 

[Lubeck]

20 gal changes weekly on a 180 gal system.

 

[robert s b.]

I been doing about 40g once a month on my 175.

 

[bravanc]

i do 55 gallon once a month or so +/- week on 220 gallon tank

 

[dax123]

I usually don't like to give this advice, but it works for me. On my 125 I may do a water change every six months or so. It has probably been longer than that now. I check my kh and salinity every week or two (especially if the skimmer has been skimming wet), and check the others when I have the time. If everything is in check, I write it in the black book and move on.

When I started I did 10% a week, that changed to biweekly, then monthly, then whenever I get time. If my tank took to much time or money it would be gone, so I keep it simple.

I'm all for keeping it simple and appreciate the truthful feedback. Most would never admit to "slacking-off" in this hobby, but if you are experienced enough to do it then by all means.

 

[alton]

What ever it takes to keep your Nitrates down and Calcium up. Some of my tanks are 5 gallons a week and other one is 60 gallons a month

 

[r1racer]

On a reef (SPS) setup weekly is probably best to keep things as stable as possible. I do a 15g change every week on my 125g plus 35g sump. Be prepared to test every week before and after your water change so you get a good idea of how often you need to change and dose.

 

[UTCReefer]

On a reef (SPS) setup weekly is probably best to keep things as stable as possible. I do a 15g change every week on my 125g plus 35g sump. Be prepared to test every week before and after your water change so you get a good idea of how often you need to change and dose.

Im not trying to start a fight or argument, but you're advice is counter intuitive. If you are changing out water every week you are inherently introducing instability, further evidenced by having to test your water after doing a change, ie your levels are shifting.
Not that i recommend it but going a month, even two or dare I say it three can have the effect of creating a more stable reef tank. I did this for over a year and i had success just by being lazy. I've since moved on from this regimen to trying to keep up with a monthly water change schedule. In my experience ive found that ive had the best growth and coloration coming back from a vacation where no one touched the tank except to feed the fish. ymmv.

 

[reefergeorge]

In my experience ive found that ive had the best growth and coloration coming back from a vacation where no one touched the tank except to feed the fish. ymmv.

I guess I'm not the only one. Once I take a quick swipe with the magfloat my tank would look better than when I left it.

 

[dax123]

I started this thread asking if it was better to do smaller frequent changes vs larger infrequent ones. Based on the replies I see people on both sides of the fence, but still no good arguements for either side.

:deadhorse1: