What’s happening to my ALK?

Mr.Guy83 · Apr 13, 2021

Over the past two days my Alk has hit rock bottom and I can’t figure out why.
I know there may be signs of dosing issues even though I dose 30 min apart because my sand is hard and “clumps” together. I also dose kalk and have my skimmer with a recirculating o2 scrubber and barely can get above 8.1. The only way I’ve been able to get above 8.1 was to increase the drip rate but I then decrease my salinity because the drip rate is faster than the evaporation rate.
At the current moment I would like to focus on getting my alk back up. Because of the clumping I thought I might be adding too much 2 part so I decided to stop and the alk continued to drop.
What can I do to get things back in order?

phosphate .03
Nitrate 1
Temp 78

Randy Holmes-Farley · Apr 13, 2021

It appears you are getting substantial abiotic precipitation of calcium carbonate.

Sand hardening happens initially when the tank is set up then slows as the sand becomes covered in organics, magnesium, and phosphate, but here is my standard recommendation to reduce precipitation on sand, heaters, pumps, etc:

1. Stop all efforts to boost pH.
2. Stop dosing alk for a bit and let it decline.
3. Reduce pH by switching to a low pH alk mix like sodium bicarbonate, or a calcium organic such as Tropic Marin All for Reef.
4. Ensure magnesium is normal to high.
5. Keep organics and phosphate on the high side.

After a few days of not dosing alk, restart slowly, adding additives to a very high flow area so it mixes in fast.

Mr.Guy83 · Apr 13, 2021

Randy Holmes-Farley said:
It appears you are getting substantial abiotic precipitation of calcium carbonate.

Sand hardening happens initially when the tank is set up then slows as the sand becomes covered in organics, magnesium, and phosphate, but here is my standard recommendation to reduce precipitation on sand, heaters, pumps, etc:

1. Stop all efforts to boost pH.
2. Stop dosing alk for a bit and let it decline.
3. Reduce pH by switching to a low pH alk mix like sodium bicarbonate, or a calcium organic such as Tropic Marin All for Reef.
4. Ensure magnesium is normal to high.
5. Keep organics and phosphate on the high side.

After a few days of not dosing alk, restart slowly, adding additives to a very high flow area so it mixes in fast.

Thank you I’ll give it a try, should I do a water change during this process?