Quick question about using sodium bicarbonate solution for maintaining alkalinity

[Leaellynasaura]

Several months back when I started monitoring alkalinity and calcium levels I bought the kalkwasser starter set from BRS. I found the kalkwasser was not working for my tank as it raised the calcium a lot more than the alkalinity. The set also came with powder for making plain calcium solution and another for making just alkalinity solution. I think the alkalinity powder is just fancy baking soda. I have been using it ever since I abandoned the kalkwasser. Reading today an article mentions that solution is only intended for making large adjustments and perhaps not for maintenance. If it seems to be working as a daily addition is it fine to use in that fashion?

 

[JimWelsh]

Sodium bicarbonate is a fine daily alkalinity additive if that is what you choose to use. It has a tendency to lower tank pH temporarily, so you might not want that effect if your tank already has low pH issues.

 

[Leaellynasaura]

OK, that is a relief. I have been adding 60 mL of the solution per day to my 135 tank (200 total gallons) and 50 mL vinegar for carbon dosing and that keeps it right at 10.5 dKH and 8.4 pH.

 

[Randy Holmes-Farley Verified Community Expert]

S I found the kalkwasser was not working for my tank as it raised the calcium a lot more than the alkalinity.

While limewater will very slowly allow calcium to rise relative to alkalinity, the effect takes a long time to be noticed. If calcium is too high, it is more likely high due to the salt mix, or faulty testing.

What salt mix, salinity, and measured calcium level?

Switching to a two part system (say, sodium carbonate or bicarbonate and calcium chloride) is a fine plan, but if you do not add a balanced amount of calcium, it will steadily decline.

 

[Leaellynasaura]

The calcium always seems to stay high with little or no additions. I am using reef crystals at 1.026. The last reading for calcium was 460mg and the magnesium is always off the chart and the last reading I estimated to be 1750 ppm.

 

[Randy Holmes-Farley Verified Community Expert]

The calcium always seems to stay high with little or no additions. I am using reef crystals at 1.026. The last reading for calcium was 460mg and the magnesium is always off the chart and the last reading I estimated to be 1750 ppm.

The magnesium is likely testing error unless you added huge amounts, but that calcium level is fine.

Personally, I'd begin using a two part (or the limewater) or you will risk one day finding calcium has declined too much and you need to add a lot. That's the beauty of balanced additives such as a two part or limewater: if you track just alkalinity, calcium follows along pretty well and may only need occasional measurement and possible corrections to the dose.