http://reefkeeping.com/issues/2008-08/nftt/index.php
Burnt tips - Some users of organic carbon dosing have reported the tissue loss at the ends of their SPS. These "burnt tips" have recovered once the user reduced the alkalinity levels within their tank to alkalinity levels closer to natural seawater (7-8 dKH), pictured below. Unfortunately, the root cause for this is not known
No seu caso pode ser potassio tambem, embora para ter certeza absoluta somente com um teste.
"A potassium leak[deficiency] is relative easy to indicate. It first starts with a fading pink on Stylophora, Pocilopora & Seriatopora, followed by weak / no growth an STN in this corals.
After this you notice weak / no growth in Montipora, especially plate forming, with fading coloration turning to brown, followed by STN.
Acropora stop growth, fading to brown, become lighter tissue with washed out coloration, followed by tissue lost (STN or RTN). Blue corals only show light blue coloration.
Corals also loose their possibility to stay in strong light, tissue get burned in corals they are placed in the highlight areas, while normally they where healthy.
This situation can be caused by different things, for example heavy stocked tanks (lots of consumers), a leak of this element in the used salt mix, export via strong skimmer etc.
I had exactly those problems and within a week, after dosing K-Balance the problems have gone. I use the product since 2 month and my corals come back to how they looked before. My tank is heavy stocked and strong skimmed. In the back of the tank I have a strong / wild growth of Montipora digitata which has become very huge over the years. It looks like Montipora corals consume more potassium than others.
A hobby test kit is not available, and it also looks like that most of the K-test kits available on the market (Merck) can only be used for freshwater. Hopefully a company producing hobby test kits will realize the importance of this element to measure.
While I had a massive potassium leak, I have dosed 50 ml for three days, followed by a 10 ml dosage daily for a two week period (320 gal system). Now, after everything looks fine (growth & coloration, stop of STN & RTN) I cut the dosage down to 5 ml twice weekly. I have not observed darker tissue with this dosage. A strong accumulation of potassium can be indicated by tissue lost, beginning from the tips."








