Water chemistry

[Jmlorfam]

My new 55 gal tank is thriving so I'm not complaining. All my tests are consistently stable. My question hinges around the alkalinity of water. I understand the relationship between PH and alkalinity (the alkalinity provides the buffering capacity and keeps ph from bouncing wildly). I have researched that in a saltwater tank the target for alkalinity is >3 meq/l and a dkh range of 7-12. The question is- what is the danger of having a greater buffer capacity above the 7-12 dkh or above 4.5 meq/l? My water consistently tests DKH 14.1 with a alk of 5.03. (salifert test kit). My tank is thriving(happy fish and inverts) and I'm seeing signs of coralline algae bloom (not by design by the way). Is the train on track or am I headed toward disaster?

 

[ccCapt]

Keeping your alk above the natural seawater range of 7-11 dKH can cause abiotic (nonbiological) precipitation of calcium carbonate on your heaters or pump impellers, which in turn can drop your calcium levels.
Also, alk over 12 dKH can cause burning on many acropora corals.

What salt are you using?

 

[Jmlorfam]

Petco premium marine salt. I suspected the salt i use was the reason for the high results. I bought a large 5 gal tub of this crap too. could this explain the unintended coralline algae bloom Im seeing in the tank? is this a self correcting problem (ie as the algae grows it will consume the calcium and lower the Dkh)? PS>anyone want to buy some marine salt? LOL!
Anyway thank you for the response.

 

[Kurt_Nelson]

"Unintended coralline algae bloom"

I don't get that term. I mean... you have no control over coralline algae - it just happens... assuming you have some in there to start with and your calcium levels are above 360. I'm not sure how you can have an "unintentional" one when you really can't have an "intentional" one.

High alkalinity doesn't necessarily mean you're headed for disaster. It just means that you might have some water parameter issues, as ccCapt mentioned, and that some corals won't do as well as others. Going from memory here, but I also think that Trachyphyllia (LPS - open brain coral) don't care for high alkalinity.

What are your calcium levels? Are you adding any buffering supplements or using any 2-part cal/alk solutions?

 

[Jmlorfam]

Unintended, as in i wasn't trying to grow it yet. I was focused on the tank set up. There was coralline on the LR I put in the tank but it was not a priority. My priority was to get this tank stable and (as this site suggests) sloooowly over time add the goodies. Coralline would be a nice touch but I dont know enough about it to be comfortable with encouraging it. I guess i need to get additional testing supplies to see what the calc hardness levels are. So i am clear, its not an immediate problem, but potentially harmful to equipment and certain species. I am not adding anything to the tank supplemental (other than what is in the marine salt). I think i understand. thank you again