View Full Version : Bleaching SPS caused by too high ALK?

05/30/2017, 08:38 AM
I am running an ULNS for the first time. Nitrates currently between 2 and 3. Phosphates at 0.01.

Since I started dosing carbon I have noticed my SPS are bleaching and my zoanthids do not open all the way.

ALK is currently at 9.0, but I have been reading that when nutrients are low you should be running ALK closer to 7-8.

Could this be my problem? Calcium is 480 and Magnesium 1400. Lighting has not changed. I am using the Red Sea NOPOX and also dose their reef energy A and B products. I feed pretty heavily.

05/30/2017, 08:51 AM
I should add that I have been dosing slooooowly with Carbon. taking my nitrates from 9 to current over about a 3 week period. I dose about 1/4th the recommended dosage.

05/30/2017, 09:23 AM
First, I think you need to determine whether what you're experiencing is a result of Bleaching or Lightening. Bleaching is a response to one of several stressors (temperature, light, others). Lightening seems to be related to low nutrient availability.

If it is in fact bleaching, you need to identify what the cause is. I'm not aware of Alkalinity swings as a cause of bleaching, but I'm also new to SPS (I just have been reading a lot).

The general consensus with Alk, at least in my reading, is to make changes slowly, especially when raising Alk.

05/30/2017, 10:46 AM
Well they are turning white and some have dies after tissue lost. I read that to high of ALK can burn SPS. If it is too low of nutrients, how do I make sure I correct that other than dosing things like Reef Energy?

05/31/2017, 07:38 PM
check your salinity. that can cause bleaching as well.

05/31/2017, 09:01 PM
How fast are they dying? I'm just trying to understand if it's STN/RTN or bleaching.

05/31/2017, 09:05 PM
First, that is not ULNS. That is not really LNS. Eventually, you might need to get to 7 alk, but not yet. Even if it was this, they don't bleach, the tips die since the coral will calcify faster than the tissue can grow - burnt tips.

Alk or N and P levels in that range should not mess with your zoas at all. This is a second clue to look elsewhere, IMO.

I think that it is more likely that your organic carbon dosing has cleared the water up some and more light is penetrating? ...or something else.

Carbon dosing can be quite dangerous in a reef. Are you sure that you need to do this? One slip up and you can damage your SPS that take a year to recover.

06/01/2017, 08:28 AM
I have dosed a lot of vodka and vinegar with alk of 8.5 or 9 for a long time. My nutrients read 0 for po4 and nitrate but I feed a ton of food. The amount of food going into a system is what determines how low your alk should be when using a lot of carbon sources. People who don't even feed the fish much at all need to keep their alk under 7.5 or their tips will burn quickly. I have seen all go up to 10 a few times in my system with no issues.
I agree with new and look elsewhere. But pictures and more info would be needed to help you any further.