High Alkalinity

[Chris’s fish]

I have a new frag tank that is cycling and I want to add coral, but the alk is super high. It’s at 14.5 by my Hanna tester. Is this too high for coral and if it is what can I do to lower it? I’m using rodi water and everything else looks good

 

[Thor2j]

What salt are you using?? Did you dose??

 

[Acrofiend]

With high alk you’ll want high nitrates and phosphates. My alk recently reached 15 dkh pegging my pH and I didn’t have any deaths. If you don’t feel comfortable with the high alk Randy has recommended dosing muriatic acid (Purchased from Home Depot). Just make sure you aerate the water because it will drop pH resulting in fish and coral death. I had luck dosing 1ml into my skimmer.. I’m SPS dominant by the way.

 

[Chris’s fish]

What salt are you using?? Did you dose??

I haven't dosed yet, just saltwater with Natures ocean reef salt.

 

[Chris’s fish]

With high alk you’ll want high nitrates and phosphates. My alk recently reached 15 dkh pegging my pH and I didn’t have any deaths. If you don’t feel comfortable with the high alk Randy has recommended dosing muriatic acid (Purchased from Home Depot). Just make sure you aerate the water because it will drop pH resulting in fish and coral death. I had luck dosing 1ml into my skimmer.. I’m SPS dominant by the way.

Thanks for the advice. I can try the acid

 

[nereefpat]

I would not try to adjust alk in a display tank by adding acid. The suggestion of adjusting alk with acid is okay in water change water, but not a great idea in a tank with animals in it.

 

[Chris’s fish]

I would not try to adjust alk in a display tank by adding acid. The suggestion of adjusting alk with acid is okay in water change water, but not a great idea in a tank with animals in it.

Currently I have no animals in it. What else would you recommend though? And do you think it is ok for the alk to be that high? Once I add corals I assume it will drop quickly, no?

 

[nereefpat]

Currently I have no animals in it.

Then it's probably okay to add the acid, slowly.

What else would you recommend though?

The only good ways to lower alk in a display with animals is to do water changes with lower alk salt and to let it come down on its own.

And do you think it is ok for the alk to be that high?

That's really high compared to seawater (7 dKH). Some reefers keep it much higher than seawater, but 14.5 is really high. I would suggest comparing that Hanna meter to a titration test.

Once I add corals I assume it will drop quickly, no?

Frags don't use it quickly. Coraline algae can use a lot. Somewhere in the order of 0.5-2 dKH use per day would be a normal range.