High KH & MG with steady PH & CA - is that a problem??

scoopsthedog · Mar 12, 2017

So with my 50G mostly LPS / zoa/ softie tank I've been getting pretty consistent high KH (11-12) and MG (1380-1500) but my CA has been steady (450-480) as has my PH (8.3 with one drop to 7.8 which I corrected). I'm pretty sure my KH stays high because I dose sodium bicarbonate (Vitamin C) which has correlated with new Zoa growth.

I was dosing a Multivitamin weekly and reef advantage for CA but stopped once I found my weekly 10% water changes with Red Sea salt mix kept the parameters high.

Are there any long term issues with keeping KH in the 10-12 range? Should I lay off the Vitamin C for a week and see what happens?

scoopsthedog · Mar 12, 2017

scoopsthedog · Mar 12, 2017

Bumpy bump. Bueller?

Randy Holmes-Farley · Mar 13, 2017

scoopsthedog said:
So with my 50G mostly LPS / zoa/ softie tank I've been getting pretty consistent high KH (11-12) and MG (1380-1500) but my CA has been steady (450-480) as has my PH (8.3 with one drop to 7.8 which I corrected). I'm pretty sure my KH stays high because I dose sodium bicarbonate (Vitamin C) which has correlated with new Zoa growth.

What do you dose? Vitamin C is not sodium bicarbonate. Vitamin C is ascorbic acid or sodium ascorbate.

How much do you dose?

I'm not convinced that Vitamin C is particularly useful to reef tanks (relative to other organic carbon dosing), but I know that at least for a while many people experimented with it and some people thought it useful.

In general, if nutrients are not particularly low, alkalinity at 11 dKH is fine. Some hard corals grow faster at higher alkalinity.

scoopsthedog · Mar 13, 2017

Randy Holmes-Farley said:
What do you dose? Vitamin C is not sodium bicarbonate. Vitamin C is ascorbic acid or sodium ascorbate.

How much do you dose?

I'm not convinced that Vitamin C is particularly useful to reef tanks (relative to other organic carbon dosing), but I know that at least for a while many people experimented with it and some people thought it useful.

In general, if nutrients are not particularly low, alkalinity at 11 dKH is fine. Some hard corals grow faster at higher alkalinity.

Sorry you are correct Sodium Ascorbate is what I've been dosing. I dose 1/4 teaspoon 2x daily (but now every other day due to high LH). It is def correlation but I've seen faster Zoa growth with dosing vs without and very little impact on my levels except KH which it seems to keep in the 11-12KH range. I've monitored my CA and MG and they are also so far staying high.

Randy Holmes-Farley · Mar 13, 2017

As long as nutrients do not get too low, 11-12 dKH won't be a problem. Many salt mixes start there. That may even be why it is where it is in your tank.

1/4 teaspoon is probably about 2 g, or about 10 milliequivalents of alkalinity.
In 50 gallons, you are probably adding about 10 meq/50 gallons = 0.15 dKH per day.

That is a very small addition, but if you have no coralline or any hard corals, it may accumulate.

FWIW, you might also get fast growth with other types of organics dosed too, such as vinegar. Various organics can be used by corals, and vinegar (acetate) is known to be.