Extremely slow growth

[kinerson]

My zoo's grow extremly slow. I have some orange and green "eagle eyes" that I think are actually slowly dieing. In my old tank years ago the would grow at a reasonable rate. Now, it's terrible. My nitrates are almost undetectable. Is this the problem? All other levels are normal/ideal. Lighting is on the mid to upper level and flow is moderate. I do have another type of zoo that grows at an exeptable but slow rate. However the Eagle Eyes I fear are wasting away.

Thanks,
Greg

 

[lovethereefer]

what is mid to upper level lighting? do you feed them?

 

[caddisfly]

I have had the same problem for the past 6 months or so. I had tried everything I could think of to help the situation. About 2 weeks ago I noticed how dirty the sand in my sump was. With an old system, it is possible for phosphates and other pollutants to be release after the sand bed is saturated with waste. Anyways, I decided to take all of the sand out and replace it with new. I can't belive what a difference it has made in the main tank. Everything is happy as can be.

 

[Reef Junkie]

First off...
<img src="/images/welcome.gif" width="500" height="62"><br><b><i><big><big>To Reef Central</b></i></big></big>

Please take a closeup picture of the colony.

Please list your tank parameters, husbandry, including Alk, Cal and range of Ph (if you notice any difference).

Also, if there is anything you've done differently or added or haven't kept up with?

 

[kinerson]

Lovethereef, my lighting is 175w 15k mh with vho actinics. The zoo's are 1/2 to 3/4 up in the tank. I don't feed them, at least not intentionaly. I didn't realize you could feed them. How?

Tank parameters are as follows...
Nitrate 0
Phosphate 0
Alk 3
Ca 380
Ph 8.2-8.4
20% water changes every 2 weeks with RODI and Instant Ocean. I drip limewater to replace evaporation. I have a 6" deep sand bed and about 150lbs of live rock in my 150g tank. Also have a refugium and 2 skimmers and run carbon.

This problem has been going on since I set up this tank 2 years ago. Since I've had this tank my nitrate and phosphate has always been 0. I believe this was due to my refugium that has been growing GHA.

My old tank was a 55g with more typical nitrate levels (around 15) and my growth was good.

Greg

 

[kinerson]

I should mention that many of my other soft corals have been growing slow as well.

Greg

 

[Reef Junkie]

Have you tested your salinty lately?

 

[kinerson]

Oh yep, I forgot to include that. It's 1.026

Bill do you think it has something to do with my extremely low nitrates?

Greg

 

[Reef Junkie]

It could be. I also have other softies like a Devils hand and a Green Tyree leather. They both grow very slow.

I'd say give the slow growers some time. The ones wasting away is not a good thing. Do you skim or use carbon?

 

[kinerson]

Yes i do both. I should clarify a bit. When I said they are wasting away, this is over about 1 year. What was about 30 polyps is now down to about 17 and some are very small. I think they are starving.?. In my old tank they were spreading.

Greg

 

[jason9jay]

do you suppliment or do water changes to replenish nutrients that may be essential for growth?

 

[Reef Junkie]

Kinerson, you're probably right.
Strong skimming and carbon are great for SPS tanks, but zoas do not do well. Maybe cut back on the skimming or remove the carbon.

If you have an SPS or LPS tank, just be careful not to throttle back too much, then they will recede or turn brown.

It's a touch balancing act having a mixed tank, but it can be done.
This tank belongs to a local buddy of mine:
http://www.reefcentral.com/forums/showthread.php?s=&threadid=999446

 

[kinerson]

Jason9jay, yes I do.

Bill I think that's it to. I've been wanting to get a few sps more and more, perhaps now is the time

Thanks guys.

 

[cbashaw]

I agree with the possibility of the water being too clean for soft corals.

As for lighting:

If your tank is a 150 tall (48X24x30) then it is a very deep tank and the Par on 175w 15K bulbs is fairly low so you're going to get slow growth.

If you want better growth use 10K halides or upgrade to 250W and add more actinic if it's too white/yellow for you.

Here's a good thread to show you how much par is lost by going with a higher K bulb. It's for 250W bulbs but it will give you a good idea of how much more par you could have.

http://www.reefcentral.com/forums/showthread.php?s=&threadid=254667

 

[kinerson]

Thanks cbashaw. I actually just replaced all my lamps and went with the Iwasaki's 175w 15k's with vho actinics. The Iwasaki's are the best 175w lamp on the market for my ballast with the highest par. However, I don't think light has been the cause because I have grown these eagle eye zoa's under N.O. flourescents which is lower light then what they have been under the past 2 years.

Greg