SPS ACRO tips dyeing and brown Algae growth

[JoeBatt]

Up until about a month ago I was trying to run my 350ltr tank at elevated Ca and Kh (Ca around 485-500 Kh was 10-10.5 Mg 1350)
I was keeping the Nitrates up at around 2ppm and the Phosphates up at 0.04
I was feeding RedSea Reef energy daily (mostly)

I travel with the airlines and so I wasn't great with the RedSea Reef energy and missed a few days in a row here and there and the some of my SPS RTN'd. A few others seemed to get tip burn due to the high Kh. They also developed a brown algae growth on the dead bits. I removed the RTN'd corals from the tank.

I put this down to the fact that I wasn't good with keeping up with the energy demands of the corals with the ReefEnergy.

I decided to go back to my old regime with more normal Ca and Kh levels and slowly brought them back down to Ca of 440 Kh 8.6 Mg 1320.
Nitrates now 1 and Phosphates 0.03

I am having a problem that the tips on originally unaffected SPS are now showing the tip problems again and showing a brown fuzz on a few of the tips. Nome of the LPS are showing any problems at all and indeed I have some SPS that are also fine though they are in the minority now


Any ideas?

 

[toothman]

I think it is easier to keep acros with kh between 7-8, any higher it tends to burn tips especially with lower phosphate. I would do a 25% water change and try turning your skimmer off for a couple days and observe pe after the lights are out for a hour. See if it gets better pe. If you have gfo or carbon in, take it out and observe. Also stop dosing any carbon source for a bit or dramatically cut back.

As far as testing kh, the hanna kh is really easy would highly recommend it.

It is rather interesting that red sea instructions state that higher kh and nutrients increase growth, I do not think it is true for most corals.

 

[kevin_e]

7-8 seems low. That's below NSW, for the most part. 8-10 seems more appropriate and what most reefers strive to maintain. Have you had any swings in alk during your time away?

 

[jnw240reef]

Have to keep tank dirty with higher alk.

 

[Mortie31]

NSW alkalinity is about 6.7, for most of the sub tropical areas where our hard corals tend to come from.

 

[cubman20]

I keep alk 7.2-7.6 if it gets 8-9 things go bad

 

[sjfishguy]

I agree. Above 7.5 things start to go bad for me too. Drop alk to 7

 

[71xlch]

Ill second 8 is about as high as i like to go. There are a ton of tanks that run below 8 that look amazing. I think if you google around and see keeping your alk at 10dkh as the thinking 5-8 years ago.

 

[JoeBatt]

I will try dropping to 7.8-8.0 range and see what happens. The whole problem was due to not keeping the tank 'dirty' enough at high Kh....lets see what happens, since I have to do something or it will get worse .

Never had problems before with Kh in the low 8's ....just goes to show don't mess with whats not broken!

 

[Mortie31]

It's worth a try, go slowly and hopefully it will stop the tips burning, one thing to bear in mind a lot of the times with acros, what you see today is a result of what was happening in your tank a month ago.. Good luck

 

[JoeBatt]

Your right the time lag is a problem with Acros.... Dropping it 0.7 wish Kh over a week shouldn't cause anything worse to happen....Then wait a month and lets see