Only dosing alkalinity to maintain pH at 8.3

Miami Reef · Jun 1, 2023

Rhetorical question:

What would happen if you set up a tank’s dosing system to only dose alkalinity to maintain a pH at 8.3?

It would work similarly as an ORP probe to maintain ozone.

If pH is lower than 8.3, the alkalinity (sodium hydroxide/sodium carbonate) would turn on.

If pH is greater than 8.3, the alkalinity solutions would turn off.

Calcium is maintained around 420ppm.

Would the alkalinity get too high? What would happen if there was a large party one day (CO2). Precipitation? Would micro/macro algae bring the pH higher than 8.3?

Again, this is just a rhetorical question. I’ve always wondered about the relationship between alkalinity and pH.

JimWelsh · Jun 1, 2023

This does a decent job of describing the relationships you are asking about: https://en.wikipedia.org/wiki/CO2SYS

InactionJackson · Jun 2, 2023

I think you’d be “masking” the PH problem , I’d find another way or you might find yourself with other problems down the road. I could be wrong

JB Reefer · Jun 2, 2023

Miami Reef said:
Rhetorical question:

What would happen if you set up a tank’s dosing system to only dose alkalinity to maintain a pH at 8.3?

It would work similarly as an ORP probe to maintain ozone.

If pH is lower than 8.3, the alkalinity (sodium hydroxide/sodium carbonate) would turn on.

If pH is greater than 8.3, the alkalinity solutions would turn off.

Calcium is maintained around 420ppm.

Would the alkalinity get too high? What would happen if there was a large party one day (CO2). Precipitation? Would micro/macro algae bring the pH higher than 8.3?

Again, this is just a rhetorical question. I’ve always wondered about the relationship between alkalinity and pH.

Just use kalkwaser

((FORDTECH)) · Jun 2, 2023

Yes this would be a problem because your alk would just keep rising because let’s just say your low ph is due to high co2 in the house by time you hit 8.3 your alk will be 12-14 and keep going up

Randy Holmes-Farley · Jun 2, 2023

One could not predict what will happen to the alk because it will depend on how readily the system pulls in CO2 and how readily it consumes alk.

In any given tank, it might be a fine experiment to see how well you can control ph and what alk level gets attained.

In my tank, the alk would not get too high. With kalkwasser replacing all evaporated water, the pH was 8.3 to 8.55 without alk getting too high.