Most important parameters to keep stable for acropora

[Dolphins18]

TM hydrometer is the one. I have 2 other and can use them as long as I know what the TM reads vs them.
My skimmer removes 300ml a day and I add it back manualy. My system is large enough that 300ml does virtualy nothing to the SG though.
Stability is king.

Never seen this device. Definitely getting one tho!
I saw hydrometer and thought of this fossil I still have somewhere lol

 

[Roli's Reef Ranch]

Funny you should say that.
I just received my second Tropic Marin hydrometer( first one arrived broken)
Super delicate instrument and not something I’d recommend for daily use but is a fantastic way to check the accuracy of your hydrometer.
Mine was off one point and after I recalibrated it was spot on.

The T/Marin hydrometer is the only thing I trust

 

[homer1475]

Most important parameter....

Every single one.