RBTA vs. Coral Growth Question

[Zen685]

I got my RBTA about a year ago and it has grown steadily and split once but all of the soft corals in my stock Aquapod have stopped growing. I've replaced my bulbs regularly and done weekly water changes. Does an RBTA pull something out of the water in a small tank that corals need to grow?

 

[Toddrtrex]

It could be chemical warfare -- do you run carbon?

Also, what are your water parameters?

 

[Zen685]

I sometimes run carbon but not regularly. I've never really felt like I needed to.

Ammonia 0
Nitrite 0
Nitrate 0 after a water change, 20 right before
Phophate 0
pH 8.3 but drops to 7.8 at night
Calcium 550
Alk 100ppm (running low right now but not usually)

 

[Toddrtrex]

I would try running the carbon all the time -- especially with such a some volume of water.

And getting your Alk back to normal levels won't hurt.