ACBlinky
Premium Member
I'm at a loss and really need some help with this. The chaeto in my refugium has stopped growing, and it's causing problems. For the first time since we moved the tank last September, we're seeing measurable phosphates (0.25ppm), and it's resulting in a weird, unsightly algae/cyano bloom. Something black/brown, sheetlike with threads that wave in the current is growing on the sand in the display, and there's pale green cyano-like goo overtaking the refugium. The odd thing is, it's only in the caulerpa, sand & LR rubble section; it's not growing at all in the chaeto chamber.
About three weeks ago I started running searches on this subject, and I've found lots of threads about chaeto that wouldn't grow. I tried a few things on my own, and since searching I've tried every suggestion I've read about, but nothing's working. Here's what I've tried so far, all with zero effect. The chaeto remains dark green and brittle (breaks into tiny pieces very easily), with no noticeable growth:
- Mg was low, so I raised it (to 1250ppm). It's steady now around 1300ppm and I'm making sure to keep it there.
- Ca and alk were (accidentally) low, I fixed this weeks ago but have seen no change in the chaeto. Ca is at ~400ppm, alk is at ~4meq/L
- I've been running carbon 24/7 for the past few weeks. I wondered if it might be removing something essential, so yesterday I took it out (it was a week old)
- I tried adding some Kent Essential Elements, wondering if the chaeto was lacking potassium or one of the other components. This was only two nights ago, not sure if 48h is enough time to see change but so far, nothing's different (note - the strange algae blooms appeared well before adding the EE)
- I occasionally add iron (usually 1/4 dose), but stopped as I didn't see any change in the chaeto and I can't measure the amount of iron in the water -- I started to wonder if it was actually causing a problem rather than helping. Does too much iron stop chaeto growth?
- I've done water changes as usual (20% every 1-2 weeks), in case there are trace nutrients that are being used up
- I've tried leaving the chaeto alone, flipping it every other night, pruning it back (to see if it would stimulate new growth). No change from any of these.
One thing I have NOT done is replace the bulbs on the 2x40W PC fixture lighting the refugium. Our little patch of caulerpa is growing well under these bulbs, so I figure the problem very likely lies elsewhere.
Compared to the huge ball of chaeto, the caulerpa in our fuge is really an insignificant amount; I doubt it's outcompeting the chaeto (but I'll remove it if that's at all likely). I kept it as a supplemental food for my rabbitfish, but now that he's been sold on I just keep it because it's pretty; there's only a handful, and it would be easy to toss if need be.
The tank was disturbed about a week ago, to catch some of the big fish -- there's no doubt they were overloading the tank, and now because I moved the sand around a little (SSB, not DSB) and had some of the LR out of water for about an hour there's probably a little spike happening -- not to mention that there was a major shift in bioload, which I'm sure affects the levels of bacteria and throws things off all on its own.
That said... with measurable N and P, I was hoping my chaeto would take off and remove any excess nutrients as fast as they spiked. It hasn't really grown for quite a while, and shows no sign of starting now. OTOH, it doesn't look to be dying either -- it's not melting, turning yellow, or disappearing in any way; it's just breaking into small bits, staying dark green (used to be light green on top) and not increasing in size.
Any hints? Thanks so much for reading all that!
About three weeks ago I started running searches on this subject, and I've found lots of threads about chaeto that wouldn't grow. I tried a few things on my own, and since searching I've tried every suggestion I've read about, but nothing's working. Here's what I've tried so far, all with zero effect. The chaeto remains dark green and brittle (breaks into tiny pieces very easily), with no noticeable growth:
- Mg was low, so I raised it (to 1250ppm). It's steady now around 1300ppm and I'm making sure to keep it there.
- Ca and alk were (accidentally) low, I fixed this weeks ago but have seen no change in the chaeto. Ca is at ~400ppm, alk is at ~4meq/L
- I've been running carbon 24/7 for the past few weeks. I wondered if it might be removing something essential, so yesterday I took it out (it was a week old)
- I tried adding some Kent Essential Elements, wondering if the chaeto was lacking potassium or one of the other components. This was only two nights ago, not sure if 48h is enough time to see change but so far, nothing's different (note - the strange algae blooms appeared well before adding the EE)
- I occasionally add iron (usually 1/4 dose), but stopped as I didn't see any change in the chaeto and I can't measure the amount of iron in the water -- I started to wonder if it was actually causing a problem rather than helping. Does too much iron stop chaeto growth?
- I've done water changes as usual (20% every 1-2 weeks), in case there are trace nutrients that are being used up
- I've tried leaving the chaeto alone, flipping it every other night, pruning it back (to see if it would stimulate new growth). No change from any of these.
One thing I have NOT done is replace the bulbs on the 2x40W PC fixture lighting the refugium. Our little patch of caulerpa is growing well under these bulbs, so I figure the problem very likely lies elsewhere.
Compared to the huge ball of chaeto, the caulerpa in our fuge is really an insignificant amount; I doubt it's outcompeting the chaeto (but I'll remove it if that's at all likely). I kept it as a supplemental food for my rabbitfish, but now that he's been sold on I just keep it because it's pretty; there's only a handful, and it would be easy to toss if need be.
The tank was disturbed about a week ago, to catch some of the big fish -- there's no doubt they were overloading the tank, and now because I moved the sand around a little (SSB, not DSB) and had some of the LR out of water for about an hour there's probably a little spike happening -- not to mention that there was a major shift in bioload, which I'm sure affects the levels of bacteria and throws things off all on its own.
That said... with measurable N and P, I was hoping my chaeto would take off and remove any excess nutrients as fast as they spiked. It hasn't really grown for quite a while, and shows no sign of starting now. OTOH, it doesn't look to be dying either -- it's not melting, turning yellow, or disappearing in any way; it's just breaking into small bits, staying dark green (used to be light green on top) and not increasing in size.
Any hints? Thanks so much for reading all that!
I did notice though, that the cyano or whatever it is growing on the sand is slowing going away on its own. The chaeto doesn't look any different, but I'm wondering if it may have started growing again as a result of something I've done, and it's just not apparent yet.
