My alkalinity solution loses effectiveness

[WVU2RVA]

I thought I had figured it out last month. I bought 2 new dry bags from BRS. Calcium Bicarbonate and Soda Ash. These were mixed into my (2) 5 gallon buckets, sealed with a lid, and placed beside my sump. Once I hooked everything back up, my alk started sky rocketing.
I had not changed my dose schedule or amount. But somehow it started climbing immediately to where I needed to dial back the amount I was dosing.
That amount was really high before making the new solution- 300 ml of each every day. 250 total gallons, medium to well stocked corals.
This was a high amount to be dosing from what I’ve seen others need in the same tank type.

So, the alk was working great and so was calcium. Magnesium steady at 1450.

I needed to lower dosing every week for the first month so that alk would stay below 10 dKh.

Fast forward another month from then and now my alk is plummeting again. Within a week it has gone down into 6’s.

My buckets are half empty, solution hasn’t settled in bottom, haven’t added anything to tank, normal growth.

Can it be that temperature in my garage is effecting the solution?

Is the alk precipitating out of the bucket somehow?

Is my cheato sucking it all up?

Dosing into the refugium side of my 75g sump btw.

Pumps are calibrated. What is this nonsense!?

 

[CodyRVA]

I thought I had figured it out last month. I bought 2 new dry bags from BRS. Calcium Bicarbonate and Soda Ash. These were mixed into my (2) 5 gallon buckets, sealed with a lid, and placed beside my sump. Once I hooked everything back up, my alk started sky rocketing.
I had not changed my dose schedule or amount. But somehow it started climbing immediately to where I needed to dial back the amount I was dosing.
That amount was really high before making the new solution- 300 ml of each every day. 250 total gallons, medium to well stocked corals.
This was a high amount to be dosing from what I’ve seen others need in the same tank type.

So, the alk was working great and so was calcium. Magnesium steady at 1450.

I needed to lower dosing every week for the first month so that alk would stay below 10 dKh.

Fast forward another month from then and now my alk is plummeting again. Within a week it has gone down into 6’s.

My buckets are half empty, solution hasn’t settled in bottom, haven’t added anything to tank, normal growth.

Can it be that temperature in my garage is effecting the solution?

Is the alk precipitating out of the bucket somehow?

Is my cheato sucking it all up?

Dosing into the refugium side of my 75g sump btw.

Pumps are calibrated. What is this nonsense!?

Are you sure you mixed your solutions accurately?

 

[WVU2RVA]

Are you sure you mixed your solutions accurately?

This was my first thought when the levels increased immediately with the new solution. But just as before, the alk dropped rapidly after 1.5 month or so. With solution only half way used in the 5 gallon bucket. This is the second time this has happened.
Mixed accurately, levels look great for 4-6 weeks, bucket half used, levels start dropping dramatically.

There is an acrylic tube that goes almost to the bottom of the buckets, so pulling air from the end is not the cause.
I’ve replaced all tubing twice now within the last year.
I think the temperature swings in the garage or the shelf life of mixed solution may be the cause-just not sure this happens to anyone else

 

[LobsterOfJustice]

I think something (water conditions, changes in flow or lighting, etc) is changing your corals uptake.

 

[CodyRVA]

This was my first thought when the levels increased immediately with the new solution. But just as before, the alk dropped rapidly after 1.5 month or so. With solution only half way used in the 5 gallon bucket. This is the second time this has happened.
Mixed accurately, levels look great for 4-6 weeks, bucket half used, levels start dropping dramatically.

There is an acrylic tube that goes almost to the bottom of the buckets, so pulling air from the end is not the cause.
I’ve replaced all tubing twice now within the last year.
I think the temperature swings in the garage or the shelf life of mixed solution may be the cause-just not sure this happens to anyone else

I'm no expert, but I don't believe shelf life is your issue. Are you performing any other maintenance or changes to your system when you mix your new solutions? Or are you doing any new maintenance within that 1.5 month window that would cause your parameters to drop? Lights, GFO, Pellets, Carbon dosing, Sand Bed Clean, etc?