Nano water changes.

[sheeb]

I do water changes 2 times a year on my OG nano 16 gallon tank and it’s flawless. Coral growth is stunning, water clarity is awesome and no problems. Dosing- none besides a bit of photo every week.

on the other tank I do water changes every 2 weeks, 20% and it seems like it’s doing a lot worse. (It’s not had just nothing like the other tank) why is this?

 

[Nano sapiens]

I do water changes 2 times a year on my OG nano 16 gallon tank and it’s flawless. Coral growth is stunning, water clarity is awesome and no problems. Dosing- none besides a bit of photo every week.

on the other tank I do water changes every 2 weeks, 20% and it seems like it’s doing a lot worse. (It’s not had just nothing like the other tank) why is this?

A definitive answer that everyone can agree on is not likely forthcoming. One reason might be that you have greater stability by not altering the water chemistry in the nano like you do in the larger system every 2 weeks with the 20% change...and this is beneficial in your nano's case. Relatedly, it may be that the nano is retaining higher and more stable nutrients levels than the larger system.

In my very mature 15 yr old 12g nano, 2.5% - 2x/wk gives better results (as evidenced by coral coloration, health and growth) than my previous 5% - 2x/wk. Speculation, the aquarium naturally runs undetectable PO4 and in theory the smaller water changes would help to keep the PO4 level more stable which *may* be the main contributor to the observed better results. Could also be related to the amount of water column bacteria being removed (less water/bacteria removed at any one time, more food available for corals and other organisms).

Complex topic with lots of variables