Happens every spring. The sun moves in the sky through the year, and light hits a window it hasn't hit all winter long.
Cyano turns up. It lives on 3 things: carbon, water, and light. Any other thing---oh, it COULD use it, but take it away, and it'll use something else, so nitrate, phosphate, nutrients are all fairly irrelevant to treating this stuff. More flow won't solve it. I've had it turn up in tanks where the FISH had trouble swimming and the sand wouldn't stay put. Nope. It's an archaea, a real old thing from before the dinosaurs. It's part of every green plant on earth, so there's no dodging it. It's in your tank. Always. Just now and again it gets the spectrum of light it loves, and if you want to know where that beam is hitting your tank, try the spot where it first showed up.
What's it look like? A blush or red or brown (depending on your lights) on your sand. It gets thicker and starts producing bubbles. THose are oxygen, actually, and are harmless. It can get a quarter-inch thick and start blanketing everything in the tank. You're embarrassed to have visitors.
It is, however, not a crisis. Nothing under that blanket is really harmed. And it's easy to fix.
This is why I say everybody really should have a skimmer. If you don't, use a turkey baster as a suction device and remove as much as you can before you start this. Otherwise....
Turn out your lights. Wrap your tank in newspaper on the side facing any windows at all. Your fish will sleep through this. But they'll wake to be fed, so you can if you want, or otherwise they'll just doze, as they do through hurricanes and storms on the ocean.
Leave your lights out for 3 whole days. And have your skimmer running well. Empty it as needed. On the 4th, if you have strong coral-type lighting, use the blue actinics or twilight lighting only. Otherwise, back to normal. For coral-folk, on the 5th, bring everything back to normal.
It'll be improved. But it may not be the last you see of this pest this season. But if it recurs, bear with it for a while. Next month, same date, do the same thing. Typically, for a bad case, do this 3 months running and you should be rid of it for a while. Try not to let window-light reach your tank.
Do NOT use any red slime remover until you have a very mature tank or really know what you're doing, and even so---it may cost you your microlife, like pods, which can be hugely expensive to replace for a starving dragonet. This method works, costs nothing, and is far, far, far safer.
Cyano turns up. It lives on 3 things: carbon, water, and light. Any other thing---oh, it COULD use it, but take it away, and it'll use something else, so nitrate, phosphate, nutrients are all fairly irrelevant to treating this stuff. More flow won't solve it. I've had it turn up in tanks where the FISH had trouble swimming and the sand wouldn't stay put. Nope. It's an archaea, a real old thing from before the dinosaurs. It's part of every green plant on earth, so there's no dodging it. It's in your tank. Always. Just now and again it gets the spectrum of light it loves, and if you want to know where that beam is hitting your tank, try the spot where it first showed up.
What's it look like? A blush or red or brown (depending on your lights) on your sand. It gets thicker and starts producing bubbles. THose are oxygen, actually, and are harmless. It can get a quarter-inch thick and start blanketing everything in the tank. You're embarrassed to have visitors.
It is, however, not a crisis. Nothing under that blanket is really harmed. And it's easy to fix.
This is why I say everybody really should have a skimmer. If you don't, use a turkey baster as a suction device and remove as much as you can before you start this. Otherwise....
Turn out your lights. Wrap your tank in newspaper on the side facing any windows at all. Your fish will sleep through this. But they'll wake to be fed, so you can if you want, or otherwise they'll just doze, as they do through hurricanes and storms on the ocean.
Leave your lights out for 3 whole days. And have your skimmer running well. Empty it as needed. On the 4th, if you have strong coral-type lighting, use the blue actinics or twilight lighting only. Otherwise, back to normal. For coral-folk, on the 5th, bring everything back to normal.
It'll be improved. But it may not be the last you see of this pest this season. But if it recurs, bear with it for a while. Next month, same date, do the same thing. Typically, for a bad case, do this 3 months running and you should be rid of it for a while. Try not to let window-light reach your tank.
Do NOT use any red slime remover until you have a very mature tank or really know what you're doing, and even so---it may cost you your microlife, like pods, which can be hugely expensive to replace for a starving dragonet. This method works, costs nothing, and is far, far, far safer.
Last edited:
