Foster&Smith KALKWASSER good or bad

[Jyetman]

It seems I been having to almost double the dosage amounts to maintain ALK and Calcium. I add 5 TSP per 5 gallons and my PH meter shows kalk under 11. Why is my drip dosage increasing to maintain 10 DKH and a low CA of 380 PPM? The 5 gallons only last 2 days. My 80 gal tank is only softies but the water has high DOCs could this be the reason for higher KALK dosing? I'm also adding 2 TSP of Seachem Reef Builder to a 15 Gallon top-off bucket. Should I not trust API test kits?

 

[bertoni]

The pH meter might not be very accurate in that range. You could try adding a teaspoon of Kalk to a cup of RO/DI, and measuring that. The actual pH will be about 12.5. You can subtract the two pH readings to get an idea of concentration. I can do the math if you provide the measurements.

Some tanks consume 2-3 dKH per day due to coralline growth. Soft corals often make spicules and other calcium carbonate structures, so they can consume some calcium, too, although not nearly at the rate of stony corals. Your dosing amount seems very low to me. Assuming your tank has about 55g of actual water volume, my soft coral tanks went through the equivalent of 3 tsp per day of Reef Builder, for example, in addition to Kalk. I suspect you're seeing normal consumption.

Does the tank have any coralline? A picture might help.

 

[Dan_P]

This might be too much like chemstry lab...

You can answer your question by titrating solutions of both kalkwasser and comparing the results. I would use a pH meter to follow the titration and use the titrant in your alkalinity test. You will probably want to dilute the saturated kalkwasser solutions so you don't consume a lot of the alkalinity titrant/reagent.

There is a possibility that the kalkwasser that seems to be "œweaker" is contaminated, possibly with calcium carbonate. You might detect calcium carbonate with the titration as a pH reading that drifts over time as the cacium carbonate dissolves below pH 7.

Happy to work out details of this lab experiment if you are gungho on the idea.

 

[ramseynb]

In addition to what's already been said, what salt mix are you using? If you're using something like IO, it has low alk/calc numbers freshly mixed. It seems really odd that you'd have to dose that much in a softie tank. I never dosed anything in softie tanks I've had and everything was good as long as I stayed on top of water changes with a good salt mix.

 

[Jyetman]

I'm using Red Sea Coral Pro salt which is good salt. I have a algae scrubber so i skimp on the water changes. I actually doubled the kalk drip 5 days ago and still ALK stays at 10DKH and CA at 380 PPM no increase.

 

[hkgar]

I just received a gallon bucket of it. It tested at 9.9 dKH using 1 ml diluted with 9 ml RO water. Should be a bit above 12.

I diluted 2 tsps of drs Kalk in a gallon of water.. Fully saturated should be 123.43
https://www.hamzasreef.com/Contents/Calculators/KalkContribution.php