Recipe 1 precipitating?

[vick]

For some reason, the only way to keep my alk and calcium levels stable is to use Recipe 2. I've experimented this past week with using just Recipe 1 and my alk level went from 9.0 to 6.0. I've been adding 30mL in the morning and 30mL at night to a 55 gallon reef setup. I assume it is precipitating, but I'm not sure why. My pH is usually around 8.0 in the middle of a lighting cycle. I've read if your pH is on the low side you should be using Recipe 1. Why isn't this working for me?

[barjam]

Overdosing recipe one will cause that. What sort of tank is it? Based on your numbers that would be the amount I would expect a sps tank to consume.

I would not dose for 24 hours, note the drop in alk and use the reef calculator to decide the exact daily dose.

[Randy Holmes-Farley]

What creatures are in the tank that use calcium and alkalinity?

Why do you think it is precipitating? 60 mL in a 55 gallon system is not that much, and if you do not see precipitation, it is probably being used by things. Just add more. :)

[vick]

What creatures are in the tank that use calcium and alkalinity?

Why do you think it is precipitating? 60 mL in a 55 gallon system is not that much, and if you do not see precipitation, it is probably being used by things. Just add more. :)

I have only LPS, soft corals, and a lot of coraline algae. When I add 120 mL per day of Recipe 2, my levels are stable. I assumed adding 60 mL of Recipe 1 would keep my levels stable as well. Instead, the levels dropped significantly which is very puzzling to me. Any clue why that would happen? I'd rather not have to use the Recipe 2 because my pH is already low.

[Randy Holmes-Farley]

Dropped relative to what? How much drop over how long?

[vick]

Dropped relative to what? How much drop over how long?

While using 120mL per day of Recipe 2 over the course of a week, my alk was stable at 9.0. The next week I dosed 60mL per day of Recipe 1, and my alk dropped from 9.0 to 6.0. I feel like I should be dosing Recipe 1 because my pH is so low but I have no idea why it won't keep my levels stable.

[barjam]

While using 120mL per day of Recipe 2 over the course of a week, my alk was stable at 9.0. The next week I dosed 60mL per day of Recipe 1, and my alk dropped from 9.0 to 6.0. I feel like I should be dosing Recipe 1 because my pH is so low but I have no idea why it won't keep my levels stable.

Unless you are dosing kalk or using a calcium reactor I see no reason to chase PH. The PH is just going to adjust down to a value that is based on alkalinity and the co2 level in the air.

Generally there is no PH difference between the two recipes other than at the time of initial addition to the tank.

Maybe 30ml all at once is too much and it is precipitating out? On my tank I was having the same issue dosing 38 ml six times a day. I changed to 13 ml 12 times a day and everything is working much better.

Did your washing soda all dissolve? I had trouble getting DIY washing soda to dissolve. The stuff from BRS dissolved very easily for whatever reason.

[Randy Holmes-Farley]

While using 120mL per day of Recipe 2 over the course of a week, my alk was stable at 9.0. The next week I dosed 60mL per day of Recipe 1, and my alk dropped from 9.0 to 6.0. I feel like I should be dosing Recipe 1 because my pH is so low but I have no idea why it won't keep my levels stable.

The recipes are not interchangeable, just like other methods are not interchangeable because the demand both by organisms and by abiotic precipitation rise as pH rises. So you cannot assume that if you change pH, that the increased demand is all due to nonbiological processes. Many corals, for example, calcify (grow) faster at higher pH.