water "too clean" for softies/zoas??? Thoughts?

[futureeyedoc]

So I recently had some time to give my display tank the TLC that's it's been needing for quite some time....

My question is, I've heard before about the water being too perfect/clean and specifically zoas and other softies not performing well under such water condiitons. Is there some truth to this or is that all just talk?

My tank is a 33 long with a 20 long sump. I run a DSB in both the tank and the fuge part of the sump, and it's loaded with about 75lbs of clean LR between the top and bottom. Medium to large amount of Chaeto in the fuge. Currently running an ASM G-2 skimmer in the sump ( I know, massive overkill for a 33 long, but hey - I'm set when I move up!). Has 2 korilia 2's in the back and 2 outputs back into the tank that are generating a good amount of flow. I would rate the flow rate overall as high to extremely high for the tank size. Running 4x54 T5's. Recently purchased another cleanup crew full of crabs, snails, etc...
My water parameters are darn near perfect ( if there is such a thing):
temp 78-81
nitrates 0ppm
nitrites 0ppm
ammonia 0ppm
Calcium 400-420ppm
SG 1.023
Alk 8-10 depending on the week


My zoas did seem to be doing pretty well months ago when my tank was full of algae and just not maintained very well.... They seem to be shrinking, melting, and generally just not dong well right now while all my sps, lps, etc... are growing well...
I feed occasionally with liquid gold and phyto... proly could do that some more...

Any thoughts??? I'm thinking cut back on the skimming to a few days a week? Lose some LR?

 

[Tomoko Schum]

I don't think that your zoa problem is related to the pristine condition of your tank if other corals are doing well.

Zoanthids sometimes suffer from what some people call "small pox disease." They starts to open less and less and eventually shrink to nothing. It happens in the most pristine tanks as well as dirty ones. You need to treat them with Furan-2 (fish disease medication) which is commonly available in full line aquarium shops.

I keep my tanks pretty clean but I don't have problem growing softies. If I control my phosphate excessively, my xenia, especially pink pom poms start shrinking in size and slow down their growth rate. If another xenia is doing really well on top of it, my pompoms will gradually stop growing completely. There must be something that xenia really needs, but I seem to have a limited amount of it. They don't know how to share .

I don't see any problem with your water parameters. SG is somewhat lower than what I keep but it's still at a good level.

With that said, test kits are not made equal. I prefer Salifert and other somewhat more expensive brands that offer higher resolutions for nitrate, phosphate, magnesium, etc.

Inexpensive API is great for some basic things like kH and ammonia. But I don't trust API test kits for low-range nitrate and calcium. Their nitrate kit is meant for measuring high range nitrate and do not measure a low nitrate level well at all. You really need a low range nitrate kit for a "reef" tank. Their calcium test kit seems somewhat inconsistent, too.

 

[NicoleC]

I agree with Tomoko that it is very unlikely your water is too pristine. One thing to look at is pH. Often when algae is thriving pH is low, and zoanthids seem a lot more comfortable at a lower pH than many other corals.

One potential problem you seem to have is a large number of species of corals in a very small water volume. It seems very likely you have some significant chemical warfare going on in your tank and the zoanthids may be suffering from it. A lot of the stony corals are positively brutal, chemically. If the corals are squeezed in tightly together, it makes it worse.

BTW, what was the purpose of the clean up crew if the tank is so clean?

 

[futureeyedoc]

I had just gotten to the point where there was a lot of detritus build up mostly on the sand bed... not necesarily algae anywhere, but just more than my sand sifting star (which yes, I know is too big for a 33 long - it's a temporary thing) could handle...I've always liked cleanup crews anyways.... I don't have a fancy enough tank to worry about them destroying any coral , I think they're interesting to watch, and I also like the maintenance of the DSB they provide.... Given all that, yeah I could proly do without them and my tank would be fine....

The only weird thing is that the water quality in my 24g nano isn't nearly as good. No skimmer and I know the parameters just don't stay anywhere near as solid as the display. When I transfer zoas over there to the nanocube, there's marked improvement within a week...

It's not really like the zoas in my large tank are just completely melting away, I've just seen a lot less growth since my water went from clean to really clean.... I do use API tests for a few things but my calcium, alk, stuff like that are all much more expensive individual test kits/brands.... I use an actual refractometer as opposed to a cheaper style salinity measurement...

As far as the coral stuff goes, I think I made it sound like I have more in there than I actually do... It's mostly zoas, 1 frogspawn ( which is actually in an area near zoas where everything is doing well), and then the only hard corals I have in there are a few small caps....

Thanks Tomoko, I'll consider treating with the fish treatment and maybe upgrading the rest of my test kits....

 

[Tomoko Schum]

If your zoa thrives in your smaller tank, why not move all the zoa in there for awhile? They can use a good vacation/change of scenery, too .

 

[futureeyedoc]

yeah I had been considering the move, unfortunately it would leave me with a pretty barren display as proly at least 1/2 of my corals in the display are zoas...hmmmmm

 

[NicoleC]

If you have detritus buildup, your flow is poor. You may not need more, you may just need to rearrange what you have to get a better pattern going. Get that gunk up in the water column where it can be used as food by corals and/or exported out.

 

[scubalauren]

What is the lighting difference between your two tanks?

 

[futureeyedoc]

well, after talking to the folks at the Narc meeting I've cut back on the display... It was running 4x54w T5's - the higher PAR output ATI's with individual reflectors - but being that its only a 33 long and the tank's only about 12" deep I've determined that's still proly too much light for most stuff.... Especially considering the majority of my coral is softies and a few LPS...Cut it back to 3 bulbs for now, possibly 2 if I can stand the sight of it...Seems to be helping already...

The nano cube has a 150w 14k Halide hanging over it...Which honestly is quite a bit much as well.... I'd proly be better off with a 70w viper but oh well. Stuff does great in there, it just takes a while to acclimate to all the wattage and then it takes off...