Water changes when test readings perfect ?

[mling]

I have not done any significant water changes in about 2 months. The last 20% change was little over a month ago. I have purchase a RO system over a month ago and have not even taken it out of the box! The reading from my weekly water test have shown Ammonia, Ni & Na readings to be zero. Someone advised me that maybe my tank is doing great and I shouldn’t do anything to it. This is one of the reasons why I have not used my brand new RO system.

Do you need to do water changes when everything seems great ?

 

[comatose]

personally i would still do a water change, maybe not as much since everything is looking good, maybe 10%, you dont want to wait till something starts to show wrong before your water change then it may be to late.
how big is your tank?
and since you bought a RO unit over a month ago and haven't used it what are you using to topoff the tank?

what about other water test, Calcium, Phosphates, alkalinity ?

 

[krullulon]

i'm a strong believer in regular water changes regardless of the readings you're getting.

why? well, you're not just trying to remove things -- you're adding new trace minerals as well each time you do a water change. there are hundreds of chemical reactions happening to your tank water -- you're measuring a tiny fraction of what's going on... for example, there are trace minerals being depleted from your system each day that aren't being replaced on their own.

water quality *will* improve when you remove old system water and replace it with freshly-mixed water, even in the tests you're doing don't show a change.

 

[WannaBeReefer]

if its a reef tank, what about strontium and magnesium, iodine etc. If you dont test all these its safer just to keep doing the changes to make sure these do not get depleted.