Help with fixing my dosing.

fftfk · Aug 9, 2025

My dosing was set up by a third party and is currently set as follows:

Kalkwasser currently doses 16.5 ML Sunday, Tuesday, and Thursday for a total of 49.5 ML weekly.
Calcium currently doses 1 ML Monday, Wednesday and Friday for a total of 3 ML weekly.
Magnesium doses 20 ML Monday, Tuesday, Thursday, and Friday for a total of 60 ML weekly.
They are all generally just dumped in one batch rather than being slowly dripped over the days.
The images show the current programing.

Does this make sense to anyone? I was always under the impression you wanted to stability achieved by dosing small amounts each day. My alk seems pretty stable but has been drifting down from 8.5 to 8.3. My calcium has a decent swing on the days it doses - from 410 to 450. Magnesium seems fairly stable but that is such a finicky test I am not so sure I trust it.

I would like to even out the dosing schedule. What would be the best way to go about doing this?

Kalk adds both calcium and Alk...my thought is to turn off my calcium and change Kalk to dosing every day - 7 ml a day or could increase to 8 ml to balance the turning off of the calcium.

Alternatively - I could start by changing calcium to dosing each day - perhaps a ml per day.

What would be the best way to achieve stability while minimizing drastic changes to the tank that could stress the corals I do currently have?

MnFish1 · Aug 9, 2025

fftfk said:
My dosing was set up by a third party and is currently set as follows:

Kalkwasser currently doses 16.5 ML Sunday, Tuesday, and Thursday for a total of 49.5 ML weekly.
Calcium currently doses 1 ML Monday, Wednesday and Friday for a total of 3 ML weekly.
Magnesium doses 20 ML Monday, Tuesday, Thursday, and Friday for a total of 60 ML weekly.
They are all generally just dumped in one batch rather than being slowly dripped over the days.
The images show the current programing.

Does this make sense to anyone?

Not to me. There should be no need to dose magnesium that often

fftfk said:
I was always under the impression you wanted to stability achieved by dosing small amounts each day. My alk seems pretty stable but has been drifting down from 8.5 to 8.3. My calcium has a decent swing on the days it doses - from 410 to 450. Magnesium seems fairly stable but that is such a finicky test I am not so sure I trust it.

There is no rule - some people use a doser and dose 3 + times/day. Some do once a week. Mg does not need dosing this frequently IMHO. With an apex this dosing schedule does not make complete sense.

fftfk said:
I would like to even out the dosing schedule. What would be the best way to go about doing this?

Kalk adds both calcium and Alk...my thought is to turn off my calcium and change Kalk to dosing every day - 7 ml a day or could increase to 8 ml to balance the turning off of the calcium.

What are you basing this on? Is it a concern with pH- etc. The easy way to do this is to stop dosing. Check your alkalinity (pick a time when you're going to be home the next couple days at that time) - Again stop dosing Ca/Alkalinity and in 3 or 4 days re-measure your Alkalinity - Subtract from the initial value. when divided by the number of days this will tell your your alkalinity need. Then there are calculators that can give you options of how to replace your alkalinity. There are formal protocols for this - which you can look up.

fftfk said:
Alternatively - I could start by changing calcium to dosing each day - perhaps a ml per day.

Again - based on what? I think testing the alkalinity need is the best way - or ask the person that recommended this schedule. (By the way I'm not saying the schedule is incorrect, merely that it is not a common way to do it - and I'm not sure the rationale for dosing the Kalkwasser that way. But the numbers in your tank are not 'bad'?

fftfk said:
What would be the best way to achieve stability while minimizing drastic changes to the tank that could stress the corals I do currently have?

I don't see drastic changes. The alkalinity dropping could be solved merely by increasing your dosing some. The Ca changes are not significant in general - I don't see multiple days measured in your pictures - unless I'm missing it. For example you could increase your 'calcium' dosing from 3 to 4 ml for week and adjust as needed. Realize also Kalkwasser is also calcium.