Acropora frags only growing one branch

[serbusfish]

I have a number of Acro frags, three of which have shown growth since I added them, however each of these frags has only grown one branch.

I believe the ones I have are a slimer, a florida, and a millepora. Each started with around 4 branches, and with each frag one branch has grown quite noticably while the other branches havent changed.

With the Millepora and the slimer the branch that is growing is fairly white, there are visible polys but the branch is mostly devoid of colour. The florida however is just as colourful as the rest of the frag.

Is any of this normal for Acro frag growth? Or could something with my tank be off? I ensure these corals get plenty of flow and my parameters are as follows:

Temp 80'f
SG 1.025
KH 8.3
Cal 420
Mag 1350
Phos 0.03
Nitrate 5

Lighting is a Maxspect Razor 320W LED plus 2x supplemental T5's (Geisemann Aquapink and Red Sea 22k Actinic blue).

 

[Bphilpott15]

I'm new to this hobby my tank is only 1 month old just wondering why you keep you water temp at 80?

 

[serbusfish]

I'm new to this hobby my tank is only 1 month old just wondering why you keep you water temp at 80?

Its the optimum temperature IMO, if for whatever reason it rises or falls slightly from this number the aquarium occupants wont be affected.

 

[username in use]

Its the optimum temperature IMO, if for whatever reason it rises or falls slightly from this number the aquarium occupants wont be affected.

It's a little high for "optimum". It doesn't give you much space for the temerature to increase before you start having problems. You can easily drop to 72, but 84 starts to be a problem. 76-78 is kind of the dead center and gives you a good buffer in either direction.

 

[serbusfish]

It's a little high for "optimum". It doesn't give you much space for the temerature to increase before you start having problems. You can easily drop to 72, but 84 starts to be a problem. 76-78 is kind of the dead center and gives you a good buffer in either direction.

Sorry made a mistake, my tank is actually at 78f. I normally work in 'C as im in the UK, I did the conversion to F wrong. So my tank is at 26'c/78f

But anyway, back on topic, do Acros normally grow in the way I described or could something be affecting their growth? I have measured the PAR they are getting and it is in the region of 300 - 350.