BRS two part question

[saltgogi]

If I am using BRS two part for calcium and alkalinity and doing water changes every two weeks. I suppose I don't need the magnesium mix if my magnesium levels are steady and replenished every two weeks. I dose like 25 mL per day of alkalinity and 40 mL per day of calcium. So one gallon will last me a LONG time while I get all the magnesium i need from water changes. Is this correct?

Also is it odd i'm using more calcium than alkalinity? I thought it's supposed to be the other way around.

 

[Albertan22]

Yeah lots don’t end up dosing magnesium. The BRS 2 part is supposed to be a balanced mixture according to Randy Holmes Farley who developed it for BRS. Having an imbalanced dosage like that would have me questioning whether you’ve got precipitation going on. That said, it’s usually reversed like you said. Maybe check to see if your sandbed is hardening or anything like that.

 

[saltgogi]

I’m assuming precipitation from not mixing in a high enough flow area? It goes in a very high flow area. Ill have to check my sand tomorrow.

 

[Albertan22]

Not necessarily, if you dose too much it can start to precipitate, which leads to drops in parameters and the belief you need to dose more. Others can describe it better than I can as I don’t fully understand the chemistry of it.

 

[saltgogi]

Yeah I just searched videos of it. Makes sense a little more now. Thanks!

 

[Randy Holmes-Farley Verified Community Expert]

So one gallon will last me a LONG time while I get all the magnesium i need from water changes. Is this correct?

Not exactly.

The magnesium part is not just magnesium, it is also sulfate to offset the chloride addition that comes from the calcium chloride. If you were using a commercial two part like ESV B-ionic, you'd be adding this magnesium and sulfate, you just would not see it as it is mixed into the other two parts.

It will last a long time and is not very expensive and I'd use it as directed (not based on measurement), but it is also true that you are unlikely to see visual difference in the aquarium either way.

 

[Randy Holmes-Farley Verified Community Expert]

Also is it odd i'm using more calcium than alkalinity? I thought it's supposed to be the other way around.

Unbalanced demand comes from several things, including:

1. Test error/not monitoring long enough
2. Water changes with a salt mix not matching the tank parameters
3. Rising or falling or dosing of nitrate (impacts alkalinity)
4. Addition of calcium or alk in ways you do not see, like top off tap water

 

[saltgogi]

Not exactly.

The magnesium part is not just magnesium, it is also sulfate to offset the chloride addition that comes from the calcium chloride. If you were using a commercial two part like ESV B-ionic, you'd be adding this magnesium and sulfate, you just would not see it as it is mixed into the other two parts.

It will last a long time and is not very expensive and I'd use it as directed (not based on measurement), but it is also true that you are unlikely to see visual difference in the aquarium either way.

Thats good to know.
The only thing I can think of is that I recently started dosing two parts. I wanted to keep alk and calcium in same levels as the salt I used. The alk at 8.1-8.3 and calcium around 430. The only thing I can think of is that I was dosing too much alkalinity. My alk is at 9.1 and calcium at like 400-410. I'm going to do a water change today and try dosing 25 mL instead of 40 mL of each element and see if this helps.