Adding Only One Part Of Two Part OK?

[cham]

I dose 2 tsp saturated kalk for daily top off and use about 10 gallons per week. It does a great job at maintaining my CA and does OK with the alk/PH but I find that giving it a splash of randys home made alk (baking soda in RO) brings the PH from 7.9 or 8.0 range back up to 8.2 .

Is this ok to do daily and not suppliment the CA at the same time? Seems like a silly question but I know your really not supposed to dose the two part with only one part, thus the name :D

[Randy Holmes-Farley]

Continually adding just the alkalinity part will slowly boost alkalinity relative e to calcium. I'd use both parts. Calcium will shouldn't rise excessively, as it will all balance out. The only time it is OK to add just the alk part is if a salt mix like Oceanic with excessive calcium is being used. :)

[cham]

Even if my CA constantly stays at about 450 ppm?

[Randy Holmes-Farley]

If you actually want it to decline, use just the alkalinity part. But I'd use both parts unless the calcium actually gets higher than you want. Calcium responds slowly, but once you notice a drop, it will take a lot to boost it back, and you might as well add both all along.

[cham]

<a href=showthread.php?s=&postid=9264123#post9264123 target=_blank>Originally posted</a> by Randy Holmes-Farley
If you actually want it to decline, use just the alkalinity part. But I'd use both parts unless the calcium actually gets higher than you want. Calcium responds slowly, but once you notice a drop, it will take a lot to boost it back, and you might as well add both all along.

It wouldn't hurt it any to decline although I don't mind it being at 450. It just gives me room to give the tank a splash (1-2 oz) of the alk portion every morning. It gives it a nice boost from 8.0 to 8.2.

Is it possible that more alk is being used than the CA portion? I always thought with calcification it had to use both equally.


Maybe I will keep dosing alk daily in small amounts and just make sure to balance that out with the CA a couple few times a week.

[Randy Holmes-Farley]

No, it is not possible that it is using a lot more alkalinity than calcium in the short term (long term, yes). The mix ratio may also be off. Long term there are effects, like magnesium getting into CaCO3 that may play a role. But what most folks observe short term is usually an illusion of the relative usage. I discuss these here:

When Do Calcium and Alkalinity Demand Not Exactly Balance?
http://reefkeeping.com/issues/2004-12/rhf/index.htm

[cham]

I was just doing a water change and thought of something.


I am boosting my CA levels by 70 ppm with DOW flake for each water change and my MG 150 using Epsom and MAG flake but I am NOT dosing anything for alk.

I am using IO that is famous for being low in alk. Could this be where I am losing the alk from? I never noticed you saying how or if you boost yours, if so can I just add X amount of home made baking soda two part to my water change water?

I have a very similar set up to yours where I make up large batches in Brute cans, except I do water changes manually.

[cham]

bump

[Randy Holmes-Farley]

Instant Ocean now usually has about 4 meq/L (11 dKH) for alkalinity these days, so it has more than calcium, compared to seawater.
But water changes can certainly cause changes when using a balanced additive. With similar additions, mine runs about 450 ppm calcium also. :)

[cham]

<a href=showthread.php?s=&postid=9270758#post9270758 target=_blank>Originally posted</a> by Randy Holmes-Farley
Instant Ocean now usually has about 4 meq/L (11 dKH) for alkalinity these days, so it has more than calcium, compared to seawater.
But water changes can certainly cause changes when using a balanced additive. With similar additions, mine runs about 450 ppm calcium also. :)

So should I boost the alk too since I am boosting the CA by 70 ppm? If so, what would be a ball park # to boost it?

[Randy Holmes-Farley]

No, IO is plenty high already. Have you measured it?