when does a water change become irrelevant

[Aquattro]

Originally Posted by Proteus

Ypu could control your orp to remedy this problem though I would wonder the cost vs wc

I would then argue that controlling ORP with external influences is simply masking an underlying issue (to a degree). Again, it may extend the window, but not make it irrelevant.

[Magickiwi]

I monitor ORP because I run ozone and I do notice that after a water change my ORP reading hits the floor. I keep my tank around 325-350 between water changes but after a change it goes down into the 1xx range. It will take the better part of a week to get it back up. What does that mean in terms of the need or benefit of a WC? I dunno, but I'm not stopping my bi-weekly change to find out. I will let the braver people experiment with their tanks

Water clarity does seem better when my tank ORP is in the 350 range as does the vitality of the fish. Similarly my inverts etc. all seem to love the higher ORP readings.

[Proteus]

Originally Posted by Aquattro

I would then argue that controlling ORP with external influences is simply masking an underlying issue (to a degree). Again, it may extend the window, but not make it irrelevant.

Are you masking or remedying. If after a wc the orp goes down that's a imbalance.
My hottub for example users ozone to oxidize organics which means I don't have the chemical additives to remedy and also prolongs the time between cleaning

Truth told we would need a chemist to do a proper analysis of a tank before and after a wc to really find out the true story.