I have a 55 gal coral tank. been set up for about 2 years. been stocking it up with some sps, softies, and a couple lps. I know probabbly bad idea but anyway the they always did well until recently. seems the past week they are not comming out and the zoas aren't opening up. I've checked all the levels I can think to check. ammonia, nitrite, nitrate, PH, cal, phosphate, salt level. all seem to be perfect. the only thing i did differnt is move a powehead in a diffent place and they looked good for a while then all the sudden this happened. could moving a powerhead make this happen? I expected to make them mad for a couple days but it's been a week.
There we go, it's a good bet it's your power heads. The Koralia have been linked to serious voltage leaks in tanks that have been responsible for fish and coral problems. I personally have seen it more than a dozen times and have heard probably fifty cases that seem to correlate to it. There is a 150 on the sale board at the shop that the owner is selling because he could not keep anything alive in it although all water parameters were good all his coral would die in several days. Guess what power head he had in it. We have even had customers report the issue to Hydor who have stated that a little voltage isnt dangerous. Well maybe not a little, but in one case I had a customer measure there leakage at 30 Volts and another at close to 90V. Thats why we stopped carrying hydors about 2 years ago when this started and switched to the Seio props and vortechs.
"Lastly, the Koralia has run into some electricity leaking problems. This is when an electrically powered device that is in an aquarium leaks stray voltage into the tank. You can feel the voltage on your hand (usually through a small wound)."
If you have a volt meter you can test it to find out. The most economical replacement would be Seio prop 1000s. If you would rather have one big powerhead instead of several go with either a Tunze or a Vortech, Vortech is ready right out of the box the Tunze you have to buy extras to reach it's full potential. If you do decide on one remember to ask here first, as authorized dealers we can beat any legitimate price you will find anywhere.