Seeking help with stability - sudden alk spike?

[Punchanello]

Hi everyone,

I have a mature tank covered with coraline algae and a small handful of corals. I have been trying to get some stable parameters within range and am really struggling. I dont want to put more corals in because I can't get a level of stability and I will lose them.

I dose a small amount of kalkwasser via timer and kalk reactor every hour and maintain the big three using the balling method on top of that via a doser. Calcium is a little high at 475 (not dosing other than Kalk atm) Mag is a little low at 1300 and I'm bringing that up. Nitrates and phosphates also a bit high and I'm working on that (30 and .1 respectively). Ph is consistently around 8.15 - 8.35.

The issue is I keep getting sudden alk spikes. Here's what happens, after an alk spike, I let it drop over the course of 2 or 3 days without dosing. Let's say it gets down to 7.5, I will test with a Hanna tester morning and night every day and slowly increase the alk dose, at first to get it trending slowly upwards. I see my consumption increase and keep increasing the dose by small amounts. After a few days it gets sticky at around 8.0 or 8.1 dKH despite small increases in the dose. I'm aiming for around 8.3 to be safe because that is at the top end of my reef salt parameters.

Then suddenly, I will go from 8.1 to 9.0 or even 9.4 in a 24 hour period. I have been careful the last couple of times to make sure I'm not changing anything else to trigger it. So after that, I go through the cycle again. It's happened 4 or 5 times now.

Does anyone have any theories on why this might be happening? Grateful for your thoughts and advice.

 

[Peair]

it seems like you are doing a good job dosing, try making an adjustment on the kalk and Alk, and keep it constant.

 

[Randy Holmes-Farley Verified Community Expert]

Hi everyone,

I have a mature tank covered with coraline algae and a small handful of corals. I have been trying to get some stable parameters within range and am really struggling. I dont want to put more corals in because I can't get a level of stability and I will lose them.

I dose a small amount of kalkwasser via timer and kalk reactor every hour and maintain the big three using the balling method on top of that via a doser. Calcium is a little high at 475 (not dosing other than Kalk atm) Mag is a little low at 1300 and I'm bringing that up. Nitrates and phosphates also a bit high and I'm working on that (30 and .1 respectively). Ph is consistently around 8.15 - 8.35.

The issue is I keep getting sudden alk spikes. Here's what happens, after an alk spike, I let it drop over the course of 2 or 3 days without dosing. Let's say it gets down to 7.5, I will test with a Hanna tester morning and night every day and slowly increase the alk dose, at first to get it trending slowly upwards. I see my consumption increase and keep increasing the dose by small amounts. After a few days it gets sticky at around 8.0 or 8.1 dKH despite small increases in the dose. I'm aiming for around 8.3 to be safe because that is at the top end of my reef salt parameters.

Then suddenly, I will go from 8.1 to 9.0 or even 9.4 in a 24 hour period. I have been careful the last couple of times to make sure I'm not changing anything else to trigger it. So after that, I go through the cycle again. It's happened 4 or 5 times now.

Does anyone have any theories on why this might be happening? Grateful for your thoughts and advice.

Maybe the reactor sends some solids into the tank?