[Linda]

Wonder if any of you can help. Last week I noticedthat my small patch of orange centered zoas had closed up. The next morning there were just grey stubs and by the following morning there was no sign of where they had been.

Today, 3 polyps of my pink centered ones were closed. These are about 3 ins away from where the orange ones were. During the day they have turned grey and stubby. They almost look as though they are 'melting' - and alarmingly quickly

These 2 shots were taken at around 5 p.m.





And these were taken about 9 p.m.





Anyone know what's causing this and what I can do about it?

I have plans for a zoa garden in the tank soon so would like to sort out what the problem is if I can.

[jonothetigger]

what sort of lighting have you got !?
have you just changed your lighting ?

[Linda]

I have T5 lights, and yes I recently changed from a 3 x 39W unit to a 8 x 39W one.

Never occured to me that improved lighting might upset corals

[Kevang]

Linda, on Jan 30 2008, 11:31 AM, said:

I have T5 lights, and yes I recently changed from a 3 x 39W unit to a 8 x 39W one.

Never occured to me that improved lighting might upset corals

Did they start "melting" within a few days of putting the new lights on or was it much latter?

If it was later maybe something is having them for lunch and dinner

Have you added any new corals recently that could have brought nudi's or spiders with them



Kev

[Linda]

It must have been about 3 weeks after the new lights were up that the firsts batch went. The second ones started showing signs about 3 weeks after that.

I put 2 new corals in last week, but that was after the first batch had gone. I have looked at all times of day and night and can't see anything on them. They don't look as though they are being attacked, they just seem to close up then go grey then shrink until there is nothing left.

Have to say after the three polyps went a couple of days ago, the rest of the mat seems to be OK. (at least for now)

[Kevang]

Linda, on Jan 30 2008, 05:08 PM, said:

Have to say after the three polyps went a couple of days ago, the rest of the mat seems to be OK. (at least for now)

Lets hope that will be it

If it starts again a fresh water dip may get rid of anything that is on the rock



Kev

[Linda]

Thanks Kev. I'll keep a close eye on them, and if it starts again I'll give it a try

[Crabbit]

Did you take any precautionary measure before putting the new coral in your tank? It is good practise to fresh water dip all new zoo's and get a pair of tweezers and look for box snails and star fish that look odd shape as these eat this type of coral. I would say because your corals close up in the day and from the pictures not all of them are suffering i wouldn't put this down to your lights. Often take zoo's home and put them under 400w MH without problems. Although I'm not out ruling this. If it was spiders you would be losing corals at night but seen as you say they are melting through the day it is pointing to me that it nudibranches. I would take all of your zoo's out and give them a cold fresh water dip for 25 to 30 min. Everyone will prob ally give you a different length of time for the dip but this is what works for me. Lift the coral in and out of your tank so all in polyps close up and than place in a bucket of fresh ro water. No need to worry about the Ph as these corals are exposed sometimes at low tide and often get rained on in the wild. While dipping your corals give it a vigorous swirl in the bucket every 10 min and see what you wash off. Then before you put them back in your tank check very close with a magnifying glass to see if you see any on there or holes in the bottom skirts suggesting spiders. It is worth dipping all of your zoo's and then again in 3 weeks time to be safe. Then every new zoo coral you get dip them before you put them in your tank from now on. Be sure to wear a pair of gloves as these corals can have toxic mucus to human if on broken skin.

[Linda]

Great - thanks.

I've had these ones for a few months and they have been OK till now, but I have put other new corals in there which nasties could have come in on. I only have the one left now so it will be no problem to give it a dip.

How long would you wait after doing this before adding any new ones, just to be sure.
Any new zoas I get will now be subjected to a 'swim' before going in the tank, that's for sure.

[Crabbit]

It could be that it has taken a few months for your population to grow and have an effect on your coral. There might be eggs on the coral or underneath the rock looks like a spring made of bubbles. Best to dip your zoo's and all new ones as a standard procedure and have a real good look at the coral and rock before you put it in. The coral might take a few days to open but i haven't lost a single zoo doing a 30min yet. Also get wrasse if your tank is big enough as these little workers can eat a range of nasties. I would consider then a must with a zoo garden. I would wait 4 to 6 weeks without a problem but you can judge weather your corals are growing and are happy and add when your happy Hope all goes well with da tank Mark

Linda, on Jan 31 2008, 01:46 PM, said:

Great - thanks.

I've had these ones for a few months and they have been OK till now, but I have put other new corals in there which nasties could have come in on. I only have the one left now so it will be no problem to give it a dip.

How long would you wait after doing this before adding any new ones, just to be sure.
Any new the I get will now be subjected to a 'swim' before going in the tank, that's for sure.

[Linda]

Thanks Mark.
Do you recommend a particular wrasse? I have space for a couple more fish at least.

[jonothetigger]

a radiant wrasse
bit more of a write up here thanks to ben

[Linda]

Wow, that's a cool looking fish. Never seen one around these parts - will have to ask if they can get one for me

[Crabbit]

There isn't one wrasse that eats them because they are very clever as a large colony can change the way they taste to stop them being eaten by a certain types of fish. Your best bet to to go for 3 or 4 different types. The plan being you will have a hunting pack that will have a feeding frenzy and eat them up quickly. Or they will at least eat the eggs and keep numbers down the fresh water dips should sort out the adults. If it were me i would have a male leopard wrasse with a few female for a shoalpic here . Or can be kept on their own quiet fine. Or a jade wrasse pic here or a radiant wrasse like mentioned. A cannery wrasse pic hereAlso pyjama wrasse but i would add this one last of all as it can be a pain in the A##Pic here but a wicked fish. Or a expensive choice but not the best hunter a mystery wrasse pic here. Up to you. From my experience i would recommend adding them in all together as it can be difficult to add wrasse one at a time. When added together they settle in better because it is all new to the fish. Fingers crossed have fun.

[Linda]

Thanks for all the help and advice. Plenty to go at there - I'll see what's available.

Will keep you up to date