Zoa and low mag?

[Craigdillman]

Hey I usually try to do weekly water changes (and don't do any dosing) but last week i missed it and it stretched to like 16 days and 3 of my zoas colonies were closed up ( no sps or Lps affected)

Water tests after 2ish weeks

Calcium 400
Alk 8
Mag 1140
Phos-0.09
Nitrate 0.45

So from what all i can see is that the only parameter that really was affected was the Mag being low, would that be the cause of them closing? After a 25 gallon WC they are all opened up and looking good.

Would dosing to keep my mag up help with zoa growth or anything or is this just random ?

 

[A. Grandis]

Mg at 1140 isn't THAT bad to close zoas.
I would think that the fact you didn't change the water by itself could contribute, but also not THAT bad at all. Some times I skip a week and no problems.
Just keep in mind that zoas could close for couple of days for anything or "just because". Some times they close for a week, no problem. That just could be part of the metabolism.
Not a big deal..
The more stable the better though.

Grandis.

 

[Craigdillman]

Yea I guess i never thought of that. The mag never made sense to me but didn't know if there was some secret mag zoa thing i was missing lol

 

[A. Grandis]

It is very good to keep it at ~1350 in your case.
Yes, good for the zoas.
Most zoanthid species will appreciate stable Mg in the water.

Grandis.