View Full Version : Two of my fastest growing and Healthiest SPS corals polyps have retracted

07/10/2009, 05:13 PM
Two of my healthiest looking and fastest growing sps corals have retracted their polyps. I only got these corals about a month or two ago and they are the fastest growers out of all the ones I bought at that time. My tank did go through some rough times and I had to change all the water and replace the sand, but even after that they grew quite a bit and kept their polyps out all the time. One is a green staghorn and I'm not sure about the other. My birdsnest coral seems to still be doing great, I've had it for half a year or so now. I went ahead and did a 1/4 total water volume water change yesterday, and I've done one 2 more times previously in the past month and a half. My alk was around 15, but I got it back to around nine through the last 3 water changes, and My calcium level has stayed around 370-420. My temp is constant at 79, it varies about .75 degree F throughout the day. My magnesium level has been around 1100-1200. The coral looked fine until one day after work I got home and the polyps were retracted. Only thing I did the day before was add the recommended dose of Seachem's Calcium Advantage Plus to get my calcium back up to where it needed to be because it had dropped to 370. Any Ideas? Thanks a lot!

07/10/2009, 05:21 PM
Your parameters have been so all over the place, maybe your coral is finally healthy and keeping it's polyps in because it's healthy. Polyp extension isn't a display of health of a coral. Many people have been suggesting in the past that zeo tanks had so much polyp extension because the corals were starved (I don't believe it, but it's just an example).

Get your parameters straightened out (and consistent) for 2 weeks, then let us know how the corals are doing.

07/10/2009, 09:27 PM
This happens to me sometimes if I let my tank go a while and Ca and Alk get out of whack and then I correct it and do a lot of water changes and give it a lot of attention....super glueing frags and using epoxy and messing around.

Sometimes I wonder if the correction is causing the coral skeleton to thicken and grow faster than the polyps can handle....if that makes sense. or maybe they are just irritated with change.