losing some corals

[hagfish]

In the last 2 months or so I've started losing zoanthids like crazy as well as some ricordia yuma's. Nothing has really changed except I am getting quite a bit of cyano right now. I suspect that is from my actinic VHO's, which are due to be changed. I have new ones in the mail. In the mean time, I'm just turning them on for dusk/dawn effect for about 2-3 hours altogether and using the MH's alone the rest of the time. I think there's a chance the cyano is making the zoo's close and causing them to eventually die off. But I don't think that would effect the ricordia, but maybe I'm wrong.

My nitrates are always at around 20, which is a little high IMO. But it's mostly softies in the tank and they've typically been fine with it like this until now. I've slowly been adding a little more flow. I got a seio 820 for Christmas and used it to replace the 620 that was in there. There's about 30X turnover. Am I getting too much flow for a mostly softy tank? It doesn't really seem like too much.

I've looked very closely almost every night an hour or so after the lights go off to see if I can find any predators. I haven't seen a thing. I did find a crab running off with some zoos recently, but he's in the sump now. I have hermits and I know they can be a little risky, but I've never witnessed them cause a problem.

The ricordia that have died off are all of the same kind (same color). They're losing their zooxanthellae slowly and just melting away. I have no idea why. I had about 50 polyps of these 2 months ago. Now I have maybe 10-15.

Any ideas?

 

[capncapo]

Are they disppearing or just dying off.

If they are losing their zooxanthellae it could be a light problem but I don't know for sure if that would be the problem unless your old bulbs have shifted spectrum so drastically they they no longer produce a usable spectrum.

 

[hagfish]

I did switch MH bulbs. I had a 10000k and 6500k with actinics before. Now I have 2 14000k with the actinics. The 14000k bulbs were bought used and should be about 6 months old.

The zoo's are generally slowly closing up and staying that way for a while. Then they just dissapear.

The rics are going away pretty slowly as well. They are just turning whitish and then melting away.

 

[Letmegrow]

Sounds like a couple things.

Nudis + Nocturnal predatory worms + protozoan infections.

Are your rocks dipable ?

 

[zt444a]

Well the cyano is either flow or phosphates, and since you recently improved your flow, I'd look at phosphates.

Get yourself a phosban reactor... should knock out the cyano. That might help the softies too, but others should weigh in on this.

 

[hagfish]

<a href=showthread.php?s=&postid=9173120#post9173120 target=_blank>Originally posted</a> by Letmegrow
Sounds like a couple things.

Nudis + Nocturnal predatory worms + protozoan infections.

Are your rocks dipable ?

I've looked pretty thouroughly for predators. Although I know they can be difficult to spot. I did a fresh water dip on some of them a month or so ago. I didn't really notice any change. And I saw no obvious predators fall behind in the water. I wouldn't rule out infection. I've seen some zoo's that had tiny white spots on them. But most of them don't. If it's infection, what do I do about that?

 

[capncapo]

You might look in the Zoa forum for the Lugols Iodine dip. If it's an infection it may help. It will also kill any predators.

 

[Letmegrow]

Seachem reef dip.

 

[DrBDC]

All the above are good ideas but the lighting may need a little help anyway. Actinic bulbs are pretty much good for as long as they give enough effect for you to be happy with the look. You were running a 10,000K and a 6500K and then went to a 14,000K bulb. Unless your bulbs are 175 watt, AND the 14,000K bulb you changed to was the newer Iwasaki that is sometimes marketed as 14,000K and sometimes as 15,000K, then you cut the ppfd/par in half when you changed. And that's when comparing brand new bulbs much less older ones that have lost some intensity.

That may or may not be an issue with your current problem but it CAN be an issue in growth, etc. And possibly enough to have the corals in more of survive mode vs. a thrive and grow mode.

 

[Koddie Doo]

my guess it is the lights that is a big change in k's could be a shock what is the PAr of these?

 

[hagfish]

<a href=showthread.php?s=&postid=9173711#post9173711 target=_blank>Originally posted</a> by DrBDC
All the above are good ideas but the lighting may need a little help anyway. Actinic bulbs are pretty much good for as long as they give enough effect for you to be happy with the look. You were running a 10,000K and a 6500K and then went to a 14,000K bulb. Unless your bulbs are 175 watt, AND the 14,000K bulb you changed to was the newer Iwasaki that is sometimes marketed as 14,000K and sometimes as 15,000K, then you cut the ppfd/par in half when you changed. And that's when comparing brand new bulbs much less older ones that have lost some intensity.

That may or may not be an issue with your current problem but it CAN be an issue in growth, etc. And possibly enough to have the corals in more of survive mode vs. a thrive and grow mode.

They are 250 watt bulbs. I don't know the par values. I'd have to look at the bulbs again to tell the brand too. I knew they'd be lower PAR. But I didn't really think that would matter much to zoo's and rics since they are fine in lower light anyway. The 6500k bulb was an Iwasaki, which I believe has a really high PAR. And I think the 10,000k was a Plus, which I believe has a really low PAR. Both of the original bulbs were about 6-7 months old anyway so they were getting close to needing changed.

If the problem is the light change, what can I do about it? Just wait it out? Longer photoperiod?