Zoas with small and spread out polyps

[ChantalWK]

Hi! My tank is almost 1 year old and I'm having some trouble with zoas size. I have a post for it here.

I like big polyps and "fluffy" colonies, but mine are spreading out and small.

My params are:

Lighting: Nour by OceanTech (brazilian brand), I was running it really high, 90% blues with a curve, I reduced it a couple of days ago:

salinity: 1026 (consistently)
pH: 7,8 (consistently)
KH : 5,5 / ALk/meq/l 1,5 (lower than usual, but it is consistently on the lower end)
Calcium: 400 (consistently)
Magnesium: 1310 (consistently)
ammonia: 0 (consistently)
nitrites: 0 (consistently)
Nitrates: 0,2 (consistently)
phosphates: 0 (consistently)

Supplementation:
1ml of Fuel, bi-weekly
1ml of zooplankton and phytoplankton by seachem, weekly

Feeding:
SPS powder weekly or bi-weekly

I know that my phosphates and nitrates are too low for zoas but I don't know what can I do. I was feeding more often with reef roids and special food for SPS but didn't noticed any improvement in these parameters, I was doing a lot of tests.

Recently I was a little negligent to my reef and wasn't feeding at all, was changing water less often... zoas din't seem to mind but my trumpet and plate were very upset and started shrinking. Lesson learned. Now I'm back to my routines.

Top colony (mixed nirvana and pink hippo) was just added from a friend's tank.

It is a lighting issue? I'm testing going down to 70% in my lighting.


It is a nutrition issue?

Thanks!

 

[TX_REEF]

they look quite healthy to me.

Zoas are not too picky on lighting in my experience, so I think your problem is probably your near zero N and P. Do you run a skimmer? You can try switching it off to run only at night. For me, I turned off my skimmer and fed reef roids a couple times a week and that cured my zero nutrients problem. I have a colony of orange bam bam zoas that are growing quite densely.

Reef roids for consideration: https://amzn.to/4aJgzb3
coral feeder: https://amzn.to/4aBu4cM

 

[ChantalWK]

Thanks!

In comparison with my friend's tank my zoas are miniatures, his zoas are huge. But he has a large display one of the most beautiful tanks I've ever seen.

I use reef roids once a week. I was testing twice a week or even more often. My parameters didn't budge but I 'll try feeding more often again because they might get some extra nutrients even that it doesn't show on tests.

I don't run a skimmer, I just use some biological media in the lateral sump (it's a tiny display).

How long should I observe to notice changes? Weeks? Months?
Will tiny polyps ever get bigger or just new polyps will show improvement?