I think I have LPS dialed in, but not my Zoas or soft coral.

[LittleFidel]

Hi friends.
I have some LPS frags that I care for in a 20 gallon with no other inhabitants. I target feed them regularly and they seem to grow well. My soft corals, on the other hand, are confusing me. I have them in a 29 gallon with two clownfish, lots of CUC, chaeto and red gracillaria. I have a handful of cheap zooanthid frags and a pulsing Xenia colony. The Xenia grew from two small frags and now covers an entire rock. It used to extend and have huge trunks but now it is very short and rarely extends. I got 10 zooanthids in a grab bag and several of them died back and were eaten by crabs. The remaining frags seem to be sad. They don’t spread quickly, they aren’t open all the time. What do I need to be doing to ensure they’re as happy as the LPS are?

 

[Clowns-corals-cats]

What are your nitrates at in the softie tank? They like dirtier water. And when I had xenia my pH effected them more than any other corals when it got low.

 

[Clowns-corals-cats]

Could be something in there eating them I don't think crabs would untill they are already dead. What lighting are they under

 

[LittleFidel]

Great question, to which I do not have an answer. I will check next time I am home. My guess is that N is quite low for two reasons:
1) I recently moved and did a 100% water change, which removed all nutrients
2) I have lots of macroalgae which remove nutrients from the water column

If they like dirtier water but I tend to do frequent changes to keep the bare bottom clean, is it best to dose liquid nutrients? Can the softies and the LPS get along with regards to water quality or is it best to keep them separate?

What are your nitrates at in the softie tank? They like dirtier water. And when I had xenia my pH effected them more than any other corals when it got low.

 

[LittleFidel]

Could be something in there eating them I don't think crabs would untill they are already dead. What lighting are they under

They are under 7000k daylight LEDs meant for freshwater planted tanks. I figured they’d be good for the macroalgae and I’ve heard that daylight leds can grow coral well but perhaps not color them up.
I don’t think anything is eating the healthy ones, but I am certain the crabs ate the ones that didn’t acclimate well.

 

[Clowns-corals-cats]

That light won't work. It's a different spectrum I'd switch them over to the other tank till you get another light or they are going to die

 

[Clowns-corals-cats]

They need blue light more than anything as the blue spectrums penetrate the ocean and go deeper than the others.

 

[LittleFidel]

I’m looking at .17 phosphate on the Hanna checker, 0 nitrate on the API kit, and 159 alk. It could be the light though too.

 

[RedFrog211]

Yeah, as Clown-corals-cats mentioned, corals rely on blue light. Plants and algae can use red, white and green, but corals rely on blue, as in the ocean, only blue reaches the coral at their depths. Hope your corals bounce back!

 

[LittleFidel]

So would you suggest adding an actinic 420nm strip alongside the 7000k daylight?

 

[RedFrog211]

Those could work- there’s a thread about them here: https://www.reef2reef.com/threads/420nm.637202/

 

[aydemir]

+1 on adding blue light! Actinic strip that you mentioned would work fine. I had an emerald crab that used to munch on my soft corals and LPS, and I've had emeralds in the past that only ate algae. It's kind of a tossup with crabs tbh, it may still be nipping at the corals.

 

[LittleFidel]

+1 on adding blue light! Actinic strip that you mentioned would work fine. I had an emerald crab that used to munch on my soft corals and LPS, and I've had emeralds in the past that only ate algae. It's kind of a tossup with crabs tbh, it may still be nipping at the corals.

The only crabs in there are a variety of hermits but they’re pretty aggressive and obnoxious, always trying to take food from coral. I’ll start saving for actinic lights.

 

[aydemir]

The only crabs in there are a variety of hermits but they’re pretty aggressive and obnoxious, always trying to take food from coral. I’ll start saving for actinic lights.

I've only had the small dwarf blue legged hermits and scarlet reef hermits in the past with no issues. I never tried any larger ones though. It was mainly the true crabs (like emeralds) that had a tendency to eat corals so you're probably good