High Alk Coral Burn?

[arranms96]

Hi Guys,

I am relatively new to reefing I currently have a reefer350, everything has been going pretty well however I recently swapped from using NSW to RedSea Coral Pro Salt and a few of my corals seem to be losing polyps/bleaching?

My ALK was previously maintained at around 9 when using NSW however now sits around 12/12.5

Could the elevated ALK be the cause of my issue? if so how to I lower the ALK and should I switch salt brand or go back to NSW?

 

[Jekyl]

I use coral pro and haven't had that issue. Alk does seem high though. Maybe the switch was made too quickly? How are your other parameters? What test kits are you using? NSW is usually low on parameters so it seems odd that after a water change your numbers got that high. Welcome to R2R!

 

[Randy Holmes-Farley]

I am not sure this is the explanation since the bleaching looks to happen at places other than growing tips, but high alkalinity and low nutrients is sometimes associated with "burnt tips", which may be because coral skeletons grow faster than tissue can keep up, leading to thin and poorly damaged tissue at the growing tips.

 

[arranms96]

Currently using Salifert

Alk - 12.5
Cal - 405
Nitrate - 0.2
Phosphate 0.03

Not currently testing for anything else, however I recently had a ICP test done I've added the result ot the main post

 

[Randy Holmes-Farley]

0.2 ppm for nitrate? That would be concerningly low, IMO.

 

[arranms96]

0.2 ppm for nitrate? That would be concerningly low, IMO.

0.2 is correct I tested last night, what should I be aiming for? I've been struggling with Low Nutrients since I switched from a Reefer170, I dont have a very big Bio load

Pair of Clowns,
Springer Damsel
Cleaner Shrimp
Peppermint Shrimp
2 Cleaner Wrasse
Benji Cardinal

 

[guylaga]

The low Nitrates could definitely contribute to burnt tips when your alkalinity is that high. Generally 1 to 10 ppm is what you should be shooting for.

But as it was mentioned seems like come of the coral are losing tissue at the base and not the tips, did you make an abrupt switch in salt, or slowly acclimate by mixing salts until you got to 100% Coral pro?