problem with zoanthid growth

i have alota types of zoanthids in my tank but they dont seem to growing fast as people say the should i probebly get 1 or 2 more polyps every month or 2 months soooo not very fast at all.....if anyone can help that would be awsome


PH 8.2
Dkh 3.9
Phosphate 0
nitrite 0
nitrate 15-20
temp 80
salinity 1.024
calcuim 460
mag ??

 

I've heard that differant zoas grow at different speeds. I recently bought a zoa rock w/ a lot of polyps but faded color that I am hoping to bring back. My params are similar to yours, and so far I've seen no growth but some improvement on the color. I think it might just take time...

Btw - I'm assuming you dkh unit is in meq/L (otherwise you're way low)

 

how old is your tank

 

for the most part your params looks good. nitrates may be a little high for good growth but i dont think that reading would slow down zoa growth too much. lighting? zoa placement? what are you using to maintain cal? age of tank? and do you have any coral predators in your tank that would keep the polyps from growing? sometimes a zoa colony will just take longer to grow. it can also take some time for a patch to find its stride but when it does it will takeoff.