What am I doing wrong? Zoa's not opening

[spankdog]

Hi all I need a little help here. I will try to make it short. I have a 90 gallon tank that's been up for about a year now. I never planned on doing sps because I thought it would be too difficult for me but now my sps is growing great while my soft corals aren't. The sps also seems to be lacking color. I have 6 frags of different zoa's and they just aren't opening up and looking like they should. Water parameters seem to be ok and I do a 20% water change every two weeks.

Temp 79
Ph 8.31 swing between 8.15 and 8.35 in 24 hours
SG 1.025
Alk 8.68 dKH
Cal 466 ppm
Mg 1360 ppm
Phos 0
Nitrate 0

Thanks

 

[kirkwood]

have you recently changed your lights or bulbs? have you tried moving them down to the sandbed? Also have you tested the TDS on your RODI recently?

 

[spankdog]

Ah forgot some details...... I have been using RODI water since day one and its 40 TDS in and 0 TDS out on the meter. I am using two ecotech radions and havent changed the programming in atleast 4 months. I have the zoa's randomly placed in my tank, some as low as the sand and others maybe 8-10" up. I have been using Salinity salt for the last few months also. I have been dosing about 1/2oz Alk each day because it just wont stay up although cal and mg seem ok.

 

[dawgface]

It's possible your water is too clean. How many fish and what and how often do you feed?

 

[spankdog]

I have 4 fish, Foxface, Purple Firefish, Clown, and a Diamond Goby. Only feeding once a day right now. I break off a small .5x.5" cube of hikari mysis shrimp and also cyclop-eeze every few days. I change my filter sock each week and have a SRO-1000int skimmer. Planning on adding more fish soon but don't know what yet. Also have some GHA on the rocks in the shady spots that doesn't want to die off. Recently added a pin urchin and some blue leg hermits.

Thanks

 

[dustin]

Are they slimy? Is the tissue actually receding? Are they touching any other corals? Also, do you have lots of crabs in the tank that are climbing on them alot? One more for you, are they secured in place or just sitting on live rock or sand?

 

[spankdog]

They are not any more slimy than usual and not touching anything. I do have something like 8 crabs in there but they aren't usually near the zoa's. I have the frags glued to my rocks and they are all spaced apart pretty far. They havent always been closed up like they are now but it seems like they have been going downhill for a while now. Maybe it is that the water is too clean.

 

[jbadd99]

Using carbon or phosphate removal? I had a problem where I didn't rinse my carbon pellets good enough and some of the "dust" irratated the zoas for a month or so. They stayed mostly closed until I had done a few water changes.

 

[spankdog]

I use BRS rox .8 carbon and GFO and rinse it well each time. I usually replace every 2 weeks when I am doing a water change. The dust could be an issue but it rinses clean very quickly.

 

[spankdog]

Just wanted to update this thread and say that my Zoa's are looking a little better every day now. I think the main reason that they weren't looking good is because i wasn't feeding enough. I started feeding more (twice a day) now and also made my feed time longer so they have more time to eat.