New tank AlK is drops quickly

[DeepSea75]

I have a new 80 gallon tank, 30 gallon sump (110 total volume) with rock I cycled for 3-4 months. I'm struggling to keep ALK stable, it drops .75dkh everyday. There are NO corals in the tank yet, just a couple of clownfish. I was dosing 25-50ml of BRS 2-part via dosing pump to help keep ALK stable but it kept dropping. I tried dosing 900ml of kalkwasser each day but that didn't work either.

I've stopped dosing everything and want to wash the tank for 48 hours to see if it settles out.

What would cause ALK to drop so quickly without coral? CO2 in the house?

I have a skimmer running 24/7.

No chaeto yet, tank is too young. that would help stabilize ph.

ALK - 7.52
CA - 383
MG - 1322
1.025
PH ranges from 8.15 - 7.93 (spikes when dosing then suddenly drops.)

 

[rc8t6353]

Like you said, your tank is new. Give the tank time to settle. In the meantime, keep doing what you are doing and keep testing.

 

[Randy Holmes-Farley]

Rising nitrate will deplete alkalinity. So will abiotic precipitation of calcium carbonate on pumps and heaters, and in a new tank, often on the new sand, where the calcium carbonate surfaces act as seed crystals for precipitation.

 

[DeepSea75]

Rising nitrate will deplete alkalinity. So will abiotic precipitation of calcium carbonate on pumps and heaters, and in a new tank, often on the new sand, where the calcium carbonate surfaces act as seed crystals for precipitation.

Thanks Randy. Any recommendations? should I hold off on dosing anything? Dose ALK minimally?

 

[Randy Holmes-Farley]

Check to see if the sand might be hardening anywhere, especially near where you add the kalkwasser.

 

[DeepSea75]

Check to see if the sand might be hardening anywhere, especially near where you add the kalkwasser.

minimal sand clumping throughout the tank, just a very small area where the return nozzle blows in the tank. I dose in a sump chamber before the return pump. I ordered a small Sicce pump to get high flow in this chamber to reduce precipitation.

 

[Randy Holmes-Farley]

minimal sand clumping throughout the tank, just a very small area where the return nozzle blows in the tank. I dose in a sump chamber before the return pump. I ordered a small Sicce pump to get high flow in this chamber to reduce precipitation.

OK, then there's probably no issue with the dosing, but I'd keep an eye on the sand. new sand clumping is a common problem It happened in my tank years ago.

 

[DeepSea75]

thanks. My other 2 systems are dialed in and I thought I knew what I was doing. Everyday is a new lesson in reefing.

 

[DeepSea75]

OK, then there's probably no issue with the dosing, but I'd keep an eye on the sand. new sand clumping is a common problem It happened in my tank years ago.

It also helps to recalibrate the trident. It was new and I calibrated it after a week of use but recalibrated it this afternoon. My alk readings are a full Dkh higher. I’ll double check with my Hannah checker. Thanks for the help Randy.

 

[Randy Holmes-Farley]

Thanks for the update!