My Rainbow BTAs not growing

[Batmoon]

So here is the thing, I got 3 tiny BTAs from a friend when he was leaving the hobby. From 3 they multiplied to 30-40 and took over a 1.5ft sized rock. I feed them frozen shrimps once in a month, I tried increasing the feeding frequency but they generally expel the excess food. It’s 2 year old mature tank(3x2x2) with minimal livestock (3 small clowns, 1diamond butterfly, 1 purple tang, 1 chocolate tang and a lyretail angel) and the water parameters/ temperature stays stable throughout. I’m not able to figure out that why are they not growing longer tentacles or just generally not growing? I use a Maxspect Ethreal Infinite light.

 

[radfly]

Because they are getting sufficient light and food. They all congregate to their preferred lighted area, then stay put. If light and food were lowered they would spread out and grow large tentacles to reach sufficient light.

 

[bradleym]

Can you please provide your parameters? Staying that small is very unusual for a BTA. Especially helpful are the following:

Temperature, salinity, alkalinity, nitrates, phosphates

 

[X-37B]

I only feed my nems every other month. When fed often they split knowing there is plenty of food avaiable.
It is strange to see so many small ones though. I had one split into 3 and one was the size of a quarter. I put it in my 13g and its doing well but still very small.

 

[higher99]

I’d love to know how you got yours top split and multiple when they first came in as little frags. Just got mines the other day from a fellow reefer here on R2R and I’d like some care guide from someone more experienced.

Tank: Mixed Reef mostly LPS & Softies.
IM Lagoon 25