Kalk and two part ?

[CrazyTom]

I have been dosing Kalk via a tunze ATO, and manually dosing two part.

I just purchased 2 BRS 1.1 ml dosing pump to automate my 2 part dosing.

Two questions:

It seems like the conventional wisdom is to continue to dose Kalk via ATO even if you are automating dosing two part.

The amount of Kalk added via ATO is going to be inconsistent ( differences in evaporation, skimming, ect).

Is there any reason to keep dosing Kalk once you are dosing for 2 part via dosing pumps?

Question 2:

Assuming 100ml of Calcium and 100ml of Alkalinity are going to be dosed at a speed of 1.1ml a minute.

Should it be all dosed when the lights are off to minimize ph swing?

The dosers will be controlled via an apex. Is it important to spread the dosing out over 8 hours or is the the 1.1ml slow enough that it does not really matter?

[bertoni]

[welcome]

Some people continue with Kalk and some don't. Either way can work. Kalk is inexpensive and it can help raise the pH a bit.

The dosing rate can be limited by a number of factors. The higher the pH and the higher the temperature, the more likely it is that precipitation will occur. In addition, the smaller the volume of water, the more precipitation becomes likely. So I personally always dosed into the display tank, to keep the supplements away from return pumps and small sump compartments. I would spread the dose out over the day, most likely. Keeping the alkalinity fairly constant probably is more important than the small pH affect.

[jimsplace]

As Bertoni said spread the doses out. I have the same size tank with an apex and dose both alk and kalk (cal too) and have it set up to dose evenly over 24 hours, just have your ATO come on at a different time. I have a small sump, so through experiance, I have moved my alk tube to dose in the DT to avoid precip on my equipment. Kalk will also help with alk & cal.

[CrazyTom]

do most people run atos on a schedule. I run mine 24/7 to

1) avoid a kalk overdose
2) keep sump level constant for skimmer operation
3) stabilize salinity.

-TL

[tmz]

I run my kalk dosing 24/7 and1.1ml dosers for baked baking soda and calcium chloride on timers as a small supplement. The kalk deals with abut 90% of the need. I like it because of it's self purification quailities and ph raising effects.

I don't worry about diurinal swings in ph much as long as the low point stays at 7.8 or above.; some large ones occur on natural reefs. I prefer the realtive constancy in sg, alk and calcium afforded by 24/7 dosing.
I do think about O2 depeltion in non photosynthetic periods and the potential for nightime hypoxia adversely affecting some corals . I a run a chaeto refguium on opposite photo period and stagger the photo period of some of the connected frag tanks to hep with that with a side benefit of CO2 uptake and a bit of ph stabilization.

[bertoni]

I think some people might run ATO on a timer, but I'd rather keep the SG stable than the pH. All organisms can regulate their internal pH quite well. It's required to keep the chemistry working. Many organisms don't osmoregulate, and change their internal SG with the changes in the water column.