General Zoa Care

[LobsterOfJustice]

I'm an acro guy. I've been in the hobby for 20 years but really havent kept zoas in almost 15 years due to keeping angels which will eat them. Recently I set up a small 8" cube on my desk and decided to try out zoas since I can't keep them in the main tank. Maybe this is the acro elitist in me but I really expected this to be a easy, low maintenance tank lol. They're doing... okay... but really could be doing better. Some are open, some are closed, some are kinda open but not all the way... only one frag has actually died though.

So my question is, in general, what do zoas like, and what in particular don't they like. High or low nutrients? Any particular parameters which they appreciate elevated, minimized, or stable? Better to err on side of higher light, or lower? Should they be fed? It's kind of blowing my mind that I've got acros growing out of the water but I'm struggling to keep a few zoa frags alive lol.

 

[LobsterOfJustice]

 

[AtlantiCat]

I struggled with a small zoa tank for over a year, then I upped my Magnesium game and suddenly they're much happier. It was in the low 1200s and they weren't having it until I got it over 1350. They don't use it, but they sure seem to want it there for whatever reason. Just my experience.

 

[rsmbudgetbuild2024]

Following along. Bought captains jerk zoa frag last week that was doing great first couple of days when I had a cb dwarf angel in the tank. It started getting nippy with a few coral Zoa included so I traded it in to my LFS for a blue cleaner wrasse and a tuxedo urchin. I think it’s either trauma from the angel or you actually have to feed Zoas specific cloudy green food.

I will also say that my calcium is right around 350-360ppm. It is not as high as I’d like and I am dosing till I am at around 420-440ppm. I am using the seachem ionic calcium with magnesium and strontium supplement it is working very well to raise these levels in my tank and eventually once I determine the calcium uptake rate I will add it in to my ATO reservoir

 

[Kodski]

Zoa's can be finicky but at the same time they are rarely in a situation that they can't adapt. In my experience, they adapt to whatever conditions you keep them in, but if you change that condition all growth halts and it takes forever to get them started growing again. From your pictures, I see thriving zoa's. Nice fluffy skirts are a good sign. They may just be gearing up to take off.

Here are some other observations I've gathered.

As said above, if you add a new frag and your tank conditions are different than where it come from, expect a little while for the animal to adjust before you start seeing growth. Typically I find that period for me about 2-3 months before I see an explosion of growth.

I find zoa's don't like elevated phosphates. Whenever my phosphates fluctuate, I can typically tell because a colony or two of zoa's will be closed. I find my zoa's do the best between .05-.1ppm. The lower the phosphates the heavier I'd supplement with coral foods and amino acids.

Lastly, I recently took down a tank and transferred all the rock and fish to a 100gal rubbermaid holding tub while I got the new tank situated. There were a couple of zoa polyps hanging on a rock or two. While I did have a light over the tub during the 6 month period everything in the tub was running, I never did a water change, tested parameters, or dosed any additives. I only topped off the tub and fed the fish. When I took the rocks out of the tub, I found those 2-3 polyps on each rock never stopped growing despite never once catering to them. Two rocks had somewhere between 60-80 polyps on the rock, and the other rock easily has over 150 polyps. Again my point of give them long enough to adapt, and they will grow. Just keep doing what you're doing and you'll see them turn around in no time.

A few helpful tips to take your zoa growth up a notch if you're looking to help them as much as possible.
- detritus builds up between the zoas. Make sure to regularily blow between the zoas with a turkey baster to clear all the crud out. You'd be amazed at how much crud they catch and how much it irritates the zoa.

- zoa's love to close up over the slightest touch. Algea, snails, and pests will cause the zoa's to close. If they are closed for more than a day. Investigate around the stalks and see if you can find out why. Many times I have removed detritus or a piece of algae and found that even after a week of being closed, the polyps will open back up within hours.

- Know your par. Best growth I find around the 70-80 par range. Yes I've kept zoa's in 200 par, they do fine and it can be argued that color changes a bit. But IMO you'll see fluffier and much healthier zoa's below 100 par.