Can dying corals raise alk?

[Nick Steele]

Okay so my tank has been sitting fishless so I haven’t done too much to it lately. Over a couple weeks my alk has risen from 10-12 I started to correct it slowly by doing 25% water changes with salt mixed at a 8.2dkh. After two water changes I had it down to 10dkh and was proud that I could get my tank into the 8-8.5 range within about a month.

Last week I had a cyphastrea that I believe doesn’t have enough light (slowly increasing over next month) and has significantly died off. Was a full 3 inch tile covered but now has next to no flesh left. Also my digi was dying slowly dying but still has a 50% flesh and great polyp extension. After my last water change my dkh was 11 and over the past 4 days has now gotten back up to 11.7. Tested with salifert and Hanna checker both the same so I’m sure it’s increasing.

Is it possible for decaying corals to release alk back into the tank at these rates? I’m at a loss for what else it could be.

 

[Lasse]

Are you dosing alk?

Sincerely Lasse

 

[Nick Steele]

Not at all tank is still relatively new. Just hit 6 months a few days ago. The first 4 months all parameters stayed stable and never moved around. But after going fishless for 2 months I checked cause some corals started to look ify.

As of now only the 4 sps frags I have look bad but the lps and softies look good and are growing.

 

[Lasse]

Your pH?

Sincerely Lasse

 

[Nick Steele]

Varies between 7.9-8.2 throughout the day/night

 

[Lasse]

Is it possible for decaying corals to release alk back into the tank at these rates?

Yes - if pH is low enough

Varies between 7.9-8.2 throughout the day/night

That´s not as low as you should expect dissolving of the calcium-carbonate.

Sincerely Lasse

 

[Nick Steele]

Yes - if pH is low enough



That´s not as low as you should expect dissolving of the calcium-carbonate.

Sincerely Lasse

Weird well thanks I’ll have to keep a closer eye on the system and see what’s up. Most things look good though so who knows