For pics of some commonly encountered zoa pests, including nudi's, see here:
Any new zoas that you get, especially colonies or larger pieces, need to be dipped to ensure none of these pests are present before placing them in your tank.
I have found a FW dip to be very helpful in removing pests. Here's the recipe I use:
-1 gal. FW, with PH and temp adjusted to match tank
-4 drops Lugol's iodine
I dip new arrivals in this solution for 3 minutes, swishing the heck out of them while in the dip in order to dislodge the pests.
Nudi eggs will not come off in a dip and need to be removed by hand. What works for me is to place a paper towel over my fingers and then hand pick them off. The eggs are slippery and resist things like tweezers, but will stick to a paper towel.
IME, zoa spiders also will not dislodge on their own in a dip and will need to be picked off with something like tweezers. Look VERY closely for spiders, they tend to blend in with the colors of the zoas they inhabit.
For most diseases in the earlier stages, the above dip works as well, although I usually dip in tankwater/SW instead of FW. I have personally found a FW dip to be mostly helpful with pests. For diseases, I use SW or tankwater in order to cause less stress to the zoas.
You can use other iodine based dips besides Lugol's. I have also used Kent Marine's concentrated iodine and Seachem's Reef Dip.
If the frag or colony is in REALLY bad shape, you can also paint the iodine solution onto the badly affected areas and let it sit out on a table or counter for 3-5 mins. Rinse well before returning to the tank.
I have found, especially with fungus, that it helps to place the affected colony or frag in high flow when returning it to the tank.
For zoa pox, a Furan-2 dip is extremely effective. For information on how to do this, see this article:
BibleSue and I have also found that for frags or colonies that are unresponsive to an iodine based dip, sometimes Furan-2 works. Always make sure you rinse before returning to the tank.
We have also found that when we get new zoas in, they do better if we leave the lights off on the first day or only have actinics on.
I'm sure I will think of things that I forgot to include in this, and will add on as time and memory allows.
Anyone else with experience in this area, please feel free to chime in.
Edited by Weetabix7, 06 November 2007 - 01:03 PM.