Have had mine for about a month rainbow bubble tip and has not seemed to grow not sure why feed it three times a week and my tank parameters are as follows. Any input would help.
Salinity - 1.025
Alkalinity - 8.9
calcium - 440
Magnesium - 1350
Nitrate - 20
Phosphate - 0.1
Agree with above. Took mine a few months just to get accustomed to everything. After that they grew like crazy. I also never directly feed them. 2 have turned into 7, largest being about 13" across. Feeding is fun, but not necessary.
I agree with jekyl. I never feed mine and they are pretty big. I do broadcasts feed the tank and have a pair or clowns. 3 times a week is probably a bit much. Just speculating from what I have read so I have no scientific data and I'm no expert. I have read that its possible feeding actually can cause them to expend more energy processing the food (food that they really don't need) than allowing them to grow using the light. Providing you have sufficient light. Again I'm just a parrot stating what I have read online. But I do have some large healthy bubble tips that I don't feed.