2 Part Question

[krzyphsygy]

I want to begin using a two part system for my first time. I have used calc reactors in the past. My tank is a new system only 6 months old. I do have a good amount of frags in the tank mostly sps frags and some LPS corals.

Based on my testing results (Salifert), my tank seems to go through ALK more than calcium. Every 3-4 days I drop about 1-2 DKH, but calcium seems to stay the same. Is this normal or is my calc test off maybe?

 

[disc1]

It is an illusion....

For every 1 dkH drop in alkalinity you only get about 2 or 3 ppm drop in calcium. That's not enough to make a difference on your test kit. But that ratio is already built into the 2 part if it is balanced properly.

The easiest / best way to dose 2 part is to do it based on the alkalinity alone. If you suddenly find that calcium is climbing, then it is likely because the salt mix is high in calcium and you can adjust the dose a little to account for water changes. But aside from that, if you make both doses the same and base the size on the alkalinity consumption you'll hit the right dose 90% of the time. That should always be your starting point at least.

 

[krzyphsygy]

That makes sense, thanks!

 

[aandfsoccr04]

It is an illusion....

For every 1 dkH drop in alkalinity you only get about 2 or 3 ppm drop in calcium. That's not enough to make a difference on your test kit. But that ratio is already built into the 2 part if it is balanced properly.

The easiest / best way to dose 2 part is to do it based on the alkalinity alone. If you suddenly find that calcium is climbing, then it is likely because the salt mix is high in calcium and you can adjust the dose a little to account for water changes. But aside from that, if you make both doses the same and base the size on the alkalinity consumption you'll hit the right dose 90% of the time. That should always be your starting point at least.

So are you saying if you are going to dose 10 grams/2.7 tsp then should you dose 10 grams of calcium as well?

 

[thegrun]

So are you saying if you are going to dose 10 grams/2.7 tsp then should you dose 10 grams of calcium as well?

Yes, if you are using balanced solutions, you should be adding the same volume of each solution (not at the same time, I dose alkalinity and calcium 1/2 hour apart).

 

[JaYbIrD1969]

Yes, if you are using balanced solutions, you should be adding the same volume of each solution (not at the same time, I dose alkalinity and calcium 1/2 hour apart).

hmmm. I didnt have any trouble with simultaneus dosing. I just dosed one in the first sump chamber and the other in the last.

 

[disc1]

No. Not ten grams to ten grams. That wouldn't be balanced at all. If you are using a commercial two part or Randy's DIY then you have set the concentration in the two solutions so that you would dose an equal volume of each. But you have to make the solutions up that way.

If you are just dosing alkalinity and calcium separately with different products then you will want to match up whatever it takes for 1 dkh with whatever it takes for 2.8ppm of calcium.

The equivalency is mole to mole not gram to gram.

 

[aandfsoccr04]

so if you are using the BRS two part dosing, soda ash and calcium bicarbonate I think, what you are saying doesn't apply?

 

[JaYbIrD1969]

so if you are using the BRS two part dosing, soda ash and calcium bicarbonate I think, what you are saying doesn't apply?

Its all about the concentration of the formula. The BRS stuff is nearly identicle to Randys. Just follow the recipe for the mixtures and dose both the Ca and Alk at the same rate.