Too powerful LED's?

[Peeleca]

I have a 20g high, which I recently purchased LED's for; a guy from my local club sold me brand new Chinese LED's. After adding them I have noticed a cyano bloom. It was isolated to the back of my tank, however is now spreading. The lights are mounted on a flower pot hanging arm. They were unintentionally mounted off center to the left, and the arm length is short which puts most of my light isolated to the back center/left. I will be correcting this in the short term. My question is, are my lights too powerful? They are 55x3w with dimmable whites and blues. My whites are on the lowest setting at approximately 20%, my blues are approximately 45%. They are 9" off the surface. I believe my lights are the source of my problem.

 

Should I raise them higher off the surface and leave the settings the way they are or should the settings be increased?

[evilc66]

What did you have over the tank before the LEDs?

[Peeleca]

I had Odseysea T5's. There was minor cyano in the same area as now, but it is much worse.

[evilc66]

You will probably have to turn the lights down a lot more than what you have them at. The Odyssea T5 fixtures aren't exactly known for being powerful. Start at 10% on the whites, and 20-25% on the blues (where ever you get the color temperature you like). Once you get the cyano issue sorted, then you can start to SLOWLY raise the intensity.

[Peeleca]

Thats the problem. I cannot dim the lights lower than 20%. The only fix to the problem that I can think of is to raise the lights higher. How high above the surface to you believe will be most beneficial?

[HeyJay]

That's a heck of a light fixure for a 20 gallon tank. As far at cyano goes, high nutrients and low flow are going to be bigger factors than your light. Add some extra flow in that area and try to do some nutrient removal. The timing of the cyano bloom after changing your light is probably a coincidence.

 

If you see some trouble with coral after adding a stronger light, you can use layers of window screen to filter the light out... start with a few layers and gradually remove them.

[Peeleca]

I have a MP10 set on Reef crest at about 80%. And I added a powerhead to that region of the tank, but it doesn't seem to be helping too much. I quit feeding frozen food a little over a week ago and I have been spot feeding the fish to cut back on excess waste. My coral has been happy with the lights. They have been in place for about a month now.

[evilc66]

That's a heck of a light fixure for a 20 gallon tank. As far at cyano goes, high nutrients and low flow are going to be bigger factors than your light. Add some extra flow in that area and try to do some nutrient removal. The timing of the cyano bloom after changing your light is probably a coincidence.

 

If you see some trouble with coral after adding a stronger light, you can use layers of window screen to filter the light out... start with a few layers and gradually remove them.

Dramatic increases in light intensity can trigger cyano and algae blooms, so it's not exactly coincidence.

 

Window screen is certainly one way to limit intensity. Raising the fixture is another. If you want to raise it up, I'd start with double the distance you have it now, and adjust as required.

[HeyJay]

Dramatic increases in light intensity can trigger cyano and algae blooms, so it's not exactly coincidence.

 

Window screen is certainly one way to limit intensity. Raising the fixture is another. If you want to raise it up, I'd start with double the distance you have it now, and adjust as required.

 

You're right, coincidence wasn't the right thing to say. Light is obviously a factor, but without excess nutrients the cyano wouldn't grow.

[Grumblecakes]

you could put a screen over the light short term to block some light. such as window screeen or nitting mesh.

[Peeleca]

Thank you guys for all the suggestions. I will put some screen on the lights for now, while I figure out how I want to raise the lights. I can either move the mount or shorten the hanging wires.

[Peeleca]

I went ahead and rose the lights, and figured I would fix my walls later. My lights are now 30" from the surface (tripling my original distance was unintentional, I goofed my measurement by measuring to the mounting bracket). I lowered the intensity of my blues to 20% and my whites on the lowest setting at 20% as well. At least with these lights I will be able to compensate for the distance. I also added from chemiclean to get ahead of this problem. I'll let you guys know how things fair in a couple of days.

[farkwar]

Poop is the cause of your cyano.

 

Not your lights.

 

Remove the poop. Cyano will go away.

[rnmike]

Poop is the cause of your cyano.

 

Not your lights.

 

Remove the poop. Cyano will go away.

He said poop!

[ew_fish]

I wouldn't say it was 100% lights.. More light helped it but its not 100% lights. More flow and water changes should help. Are you running a skimmer on your tank? If not you should invest in one.

[Peeleca]

Fixed the cyano problem. There was detritus in my sump. A filter sock resolved my problems with cyano.

 

However, I'm still having a problem with my lights. I have purchased three different birds nest and they have all lost their color. The polyps are still extended, and one of them the polyps are still colored. I am beginning to believe this lights are just entirely too powerful. My monti has fantastic color and is happy.

 

Specs of the lights

Power: 55x3w

Input Voltage: AC85-264V

Frequency: 50/60Hz

There are 55 diodes.

 

They are now 30" from the surface; whites are 30% and blues 50%

I had the lights dimmed at their lowest setting which is 20%, which is what the birds nest declined under. I have gradually increased the lights with no changes in their color.

 

The tank is a 20g High: 24" x 12" x 16"

 

 

Should I just move on to something else? This is what I get for buying a cheap light from a local reefer.

[evilc66]

I don't think the light is your issue at this point. Have you checked your water parameters to make sure there isn't something out of whack?

 

Also, it takes a lot longer to recover from bleaching than it does to actually bleach the corals in the first place. It could take months for them to recover, but if you are having new pieces bleach quickly, it's time to look at all the variables.

[Peeleca]

I performed my recent check today.

 

Mg: 1440

dKh: 9.2

Ca: 420

Nitrite, Nitrates, Ammonia: 0

1.026

76.7 F

pH: 8.0

 

My phosphates were checked at my LFS last week and they read 0. I cut my media filter off for the time being.

 

Since it was only the birds nest losing their colors and my monti were doing well I added 4 Chalice frags. 48hours later and they look awful. They no longer glow under blue lights and are very dull. I imagine they too will be white in only a couple more days.

 

 

I have an MP10 set on Reef Crest at 90%. I have a Tunze 9001 skimmer, which produces more water than actual skimmate. I feed the few SPS corals I have 1mL of Reef Energy every evening.

 

What am I missing?