Zoas not looking good

mrjohnreed · Mar 9, 2026

I have some zoas in a 3 gallon pico thats on my desk top. Some have opened up and some just dont look too good. I went through a 2 month cycle while using Dr. Tims One and Only. All parameters are within their normal readings. I do a 50% water change weekly. I have attached pics for reference of what they look like. Any info is greatly appreciated. Thanks in advance.

Dom · Mar 9, 2026

mrjohnreed said:
I have some zoas in a 3 gallon pico thats on my desk top. Some have opened up and some just dont look too good. I went through a 2 month cycle while using Dr. Tims One and Only. All parameters are within their normal readings. I do a 50% water change weekly. I have attached pics for reference of what they look like. Any info is greatly appreciated. Thanks in advance

Zoas do well with low flow and light. It would be helpful to know the light you have installed and if you are providing supplemental flow.

A full tank picture will offer a lot of info.

"All parameters are within their normal readings". This is ambiguous, as "normal readings" would depend on what you have in the tank. So please provide those readings.

A weekly 50% water change on a 3 gallon pico is a big change. You only need to do 20% of the total water volume, which in your tank would be .6 gallons.

Corals like nutrients (think nitrates). The big water change may have your nitrates down to undetectable levels. This may be the problem, or, at least a contributing factor.

Depending on your numbers, you may be able to back off on the water change frequency to get nitrates up (if they are down).

Keep us posted!
Dom

Tahoe61 · Mar 9, 2026

Lighting and intensity please.

mrjohnreed · Mar 9, 2026

The lighting is a CoralLife clip on light. The par should be fine with the highest at 30-50 par in the middle of the tank. The tank is only 12 inches deep. The parameters are as follows:
Temp. 76
Gravity- 1.024
Nitrite-0
Ammonia-0
Phosphate-0
Nitrates-0
Calcium-400
Alk- 8

There obviously looks like the water may be too pristine and cutting back on the amount of water changing could be a contributing factor. I have 2 larger tanks at home that I run a bit dirtier than this tank but I may need to run this one dirtier than normal. Since this is my 1st pico I didnt want to make too drastic of a mistake at the beginning.

mrjohnreed · Mar 9, 2026

Dom said:
Zoas do well with low flow and light. It would be helpful to know the light you have installed and if you are providing supplemental flow.

A full tank picture will offer a lot of info.

"All parameters are within their normal readings". This is ambiguous, as "normal readings" would depend on what you have in the tank. So please provide those readings.

A weekly 50% water change on a 3 gallon pico is a big change. You only need to do 20% of the total water volume, which in your tank would be .6 gallons.

Corals like nutrients (think nitrates). The big water change may have your nitrates down to undetectable levels. This may be the problem, or, at least a contributing factor.

Depending on your numbers, you may be able to back off on the water change frequency to get nitrates up (if they are down).

Keep us posted!
Dom

I have attached a picture of the tank. Its an all-in-one and I have a powerhead in there now for movement but I am looking for a smaller powerhead to replace the one I have in it now.

ColorMeGone · Mar 9, 2026

You want your N03 around 10 and your P04 around .1 to keep your zoes and other soft corals happy in my book.

GSPClown94 · Mar 9, 2026

Looks like they are all covered in sand.

ColorMeGone · Mar 9, 2026

I have 7 gals of water and do 3 cups a day w/c and have to dose N03, and P04, and Baking soda for KH to keep up with corals needs.

ColorMeGone · Mar 9, 2026

I woud also dip those frags with a peroxide solution and 80% tank water to 20% peroxide for 3-4 minutes to kill off the algae. They do not like that on them.

Dom · Mar 9, 2026

mrjohnreed said:
I have attached a picture of the tank. Its an all-in-one and I have a powerhead in there now for movement but I am looking for a smaller powerhead to replace the one I have in it now.

I'm noticing what looks to be a fresh layer of sand over old. How long ago did you place that in the tank and does the time coincide?

But zero nitrates doesn't make many corals happy.

I would cut out water changes entirely and monitor Nitrates. That should bring it up. If that doesn't do it, you could feed a bit heavier. After that, you're taking about dosing something like Neo-Nitro.

If you are delivering 50 PAR at the bottom of the tank, I'd agree that the light probably isn't the issue.

In the end, when you get things dialed in a bit more, your tank will step up to the next level.