Dark Algae on bottom

[kevvypoop313]

There is a coat of darker algae across the sand bed in my tank? What can i do. It is dark purple and brown and some black. What can i do to get rid of this. I use ro water and have hermit crabs, snails, sea urchins, and many more voracious algae eaters... what can this be?

 

[m0nk]

Sounds like cyano. There have been a bunch of threads about this lately, but here's what I posted in one of the others:
Cyano isn't actually an algea. It is actually a type of bacteria that gains it's energy through photosynthesis, which is what makes people think it's a type of algea. Because it's not an algea, there is nothing that will actually eat it. Basically you have a couple of possible problems; first is your lighting and lighting schedule, then your feeding schedule....and there are a couple of other things too, but these are the major causes.
How long do you let your lights run every day? Are the bulbs less than 12 months old? What type of lighting do you have? Is any direct sunlight hitting your tank? You should consider cutting your lighting schedule back a bit for a while, to help get rid of the cyano you currently have. Siphon most of it off the sandbed when you start the process. Slowly cut the lighting schedule back by a half hour each day until you're down to about 6 hours a day (if you use a timer this will be easy). Leave the schedule there until the cyano is gone for a few days, then you can start working with the schedule to see what works best. I keep my lights on for only 8 hours a day. Also, if your bulbs are a year old or older, change them out.
Next is nutrient levels in the tank. Phosphates can cause some trouble, but overfeeding is a big cause of other excess nutrients that also contribute to cyano growth. If you feed more than once a day, cut back to once a day. If you feed once a day, cut back to every other day. Also make sure that you only feed what your fish can eat within 5 minutes. You don't want too much food floating around after each feeding.
Good flow will also help the cyano from building up.
If you start there and the cyano persists, post back, but those two things will knock out the cyano 90% of the time. Almost every tank ends up with it at one time or another... good luck!

 

[djcanis]

I had posted a few hours ago about my problem with cyano (Red Slime). I have tried cutting my light cycle down and have also cut back on feeding, my lights are about a year and a half old. Initially, it was forming on my rock, I scrubbed it off and syphoned it out of the tank, that solved the problem for a few days but it still came back, even with only 7 hours of light and cutting back on the daily feeding again. I was told it was most likely phosphate levels in the water I am using. I tested the phos levels and there are nill. My fear is that the alge eaters I have will begin to run low on food sources as the cyano seems to be devoloping over the alge on my LR. Any further suggestions? All tests are posted in the thread "Red Slime Takeover." Thanks for the help.

 

[m0nk]

Originally Posted by DJCanis
I had posted a few hours ago about my problem with cyano (Red Slime). I have tried cutting my light cycle down and have also cut back on feeding, my lights are about a year and a half old. Initially, it was forming on my rock, I scrubbed it off and syphoned it out of the tank, that solved the problem for a few days but it still came back, even with only 7 hours of light and cutting back on the daily feeding again. I was told it was most likely phosphate levels in the water I am using. I tested the phos levels and there are nill. My fear is that the alge eaters I have will begin to run low on food sources as the cyano seems to be devoloping over the alge on my LR. Any further suggestions? All tests are posted in the thread "Red Slime Takeover." Thanks for the help.
Sounds like you need to change your bulbs, if they're the same that's been in the fixture since you bought it. Cut your lighting back to 5 or 6 hours for a week and see if that helps too. Phosphates also won't show up in your tank water if there's something consuming it. Test your mixed salt water when you prepare your next water change.

 

[djcanis]

Lights arent the orignal,I'm on my 4th set. The tank has been up over 3 years and its just in the last few months that its become a problem. I moved the tank about 6 months ago, I realized that during the day I had about 5 hours of direct sunlight through the window right on the tank. Alge growth was amazing, but I knew it wasnt good to have that much light. It seems to have developed shortly after the move. I tested my mix for phos before the last top off and it wasnt noticably higher then the tank levels. I may still be over feeding, I have noticed a large spike in my Nitrate levels. Its now up over 80. But ammonia and Nitrite are still at 0. That confuses me. Again, thanks for the help!