Sandbed precipitation

Miami Reef · Jul 24, 2023

Randy Holmes-Farley said:
I'd use baking soda to maintain 6.5 dKH for a while. Moving up too quickly will restart the process.

I was gonna say the same thing, but I know he prefers to hear it from you (how can I blame him lol)

BigMonkeyBrain · Jul 24, 2023

How is your little experiment going ? What have you learned ? You did say you have / had a dozen coral frags, how are they doing ? I have made a few aragonite rocks in my time and I just slipped them into the deep sand bed of my sump.

"When the past no longer illuminates the future, the spirit walks in darkness."
Alexis de Tocqueville

Probably happens !

drtechno · Jul 27, 2023

Miami Reef said:
I was gonna say the same thing, but I know he prefers to hear it from you (how can I blame him lol)

ROFL

BigMonkeyBrain said:
How is your little experiment going ? What have you learned ? You did say you have / had a dozen coral frags, how are they doing ? I have made a few aragonite rocks in my time and I just slipped them into the deep sand bed of my sump.

"When the past no longer illuminates the future, the spirit walks in darkness."
Alexis de Tocqueville

Probably happens !

Well.. My coral frags are ok-ish... we will see if the acros make it (green slimer, isnt that supposed to be easy?) The chalice looks pretty bad tho. But it looked a bit worse for wear after the dipping anyway.

So I am coming slowly up on the kalkwasser (1 gal per day into a 250g system volume) and boosted the alk slowly with Bicarb. I am now at 6.8 with a pH hovering 7.8-7.9

The 1 gal dosing kalkwasser appears to be holding alk stable, so I assume I have not restarted precipitation. I have learned that now I am deathly afraid of precip

I will try to break up the sand bed manually this weekend, but I'm not looking forward to it. The tank is hard to reach into and relatively deep (27")... will probably freak the heck out of the fish.

I plan on getting alk back up to 8 slowly and just maintaining these parameters for a while. I think I made some serious blunders trying to force the ph to 8.3 by dumping endless soda ash before.

drtechno · Sep 24, 2023

drtechno said:
Ya, Apex pH probe.

Yes, I calibrated it with the 7 and 10... it was 3 months ago so maybe I should recalibrate now, given that I am going to rely on it as I bring everything back online again.

Un-freakin believable. Guess what I finally did? Recalibrated my ph probe. Guess how far off it was. 0.7+. !!!
So there we go. There’s the problem. When I thought I was running a pH of 8-8.3 I was actually 9+ !!
No wonder I had precip. I cannot believe that I overlooked this. Such a basic concept of calibration and I was making decisions on bad data.

Lesson learned.

Thanks for everyone’s help.

drtechno · Sep 24, 2023

And to answer my own question. Sand hardening doesn’t go away. I had removed a bunch of hardened sand and replaced with new sand. 2 months later it’s still bricks of sand