bleaching...

[Reefer94]

A couple of months ago, the changed the 30 gallon monster, (below) into a fifty-five gallon nightmare. I've added 4 VHOs to the tank, and gotten a new skimmer. Since then, I've lost the beautiful Sarcophyton in the picture below, and all of my other corals have considerably bleached.

The colors just aren't as vivid anymore... I'm losing purple coralline (even though I have new coralline growing on the glass)... it's a ruckas. I have acouple of theories. The first is salinity. It was at about .019.... fixed that. The second was heat. The tank got into the high 80s, even 90 sometimes.... now that we're coming into winter that has changed. The third is my sandbed.

I used sand from the beach... a very fine particle size... so small actually that I have air pockets in it where water won't penetrate. There is a layer of crud developing on the surface of the sand. I'm thinking that since my sand is so fine, there isn't room for the gunk to settle in and go away... it's forming a nitrate heaven on the surface of the sand... could that be it?

Anyway... has anyone had this problem? Is there a such thing as sand that is too fine? Can my tank be too hot? Let me know, ANY input would be appreciated!!!

[Spanky]

Reefer,

Sounds to me like your sand hasn't fully cured and you are still cycling it. The air bubbles tell me it's still cooking so to speak. You're probably seeing diatom mats starting to develop on the surface.

More than likely the bleaching was caused by all the things you mentioned, and also the new lighting. Did you acclimate them to the more intense lighting?
Your loss of the old coralline indicates that your lighting is a lot stronger now. Try running your lights for a shorter period of time.

>Is there a such thing as sand that is too fine? <

Not really

>Can my tank be too hot? <

You bet, but 90's not all that bad for a very short time.

HTH
Jerel

[Doug1]

What kind of lighting did you have on the 30??
Temp could be a factor, esp if it ran lower in the 30 then got into hi 80s in the 55g. An SG of 1.019 could stress corals also.
The sand from the beach may have a lot of organics in it, it could possibly have some contaminents, but I suspect that it is cycling, hard. The layer of detritous on the sand bed indicates that you really could use more current in the tank and need to add a variety of detrivores to deal with any left overs that hit the floor.
Have you checked for Ammonia, nitrite,etc? I would make up some new SW making sure you get it 1.025, mix well over night and get to correct temp. Then get one of them siphon hoses with the wider attachment on the end and carefully siphon as much of the stuff laying on the sand surface as you can and replace a bout 5 gallons of water with fresh SW mix. Do this a couple times till you get most of it out. Add a couple powerheads and swoosh the rocks and see how much crud flies into the water column, if its a late you might add a power filter or borrow a Magnum canister filter and remove as much of that as you can.

[Reefer94]

Thanks for the input... I'm going to try another water change -- this time I'll stir up all of the crud on the bottom and try to suck it out. I'm running some big powerheads (Powerhead 801 and Maxijet 1200), but all of my flow is in the mid to upper part of the water column. Should I drop them lower? I wanted them to aggrivate the surface, while not bothering the soft corals too much. Anyway, any input would be cool. btw, the sandbed cycled with some LR and a damsel for about 4 months now.

[Doug1]

try bouncing the current from the power head off the wall and angled down slightly