auto dosing alk problems/questions

natereinhold1

New member
I have to add a decent amount of BS to my tank daily to keep it a 10-11dkh, I am thinking about using a aqualifter on a daily timer to add my BS water, is this going to be feasible until I get a CA reactor. If so what problems should i watch for? Also, is there a problem with adding to much fresh water to a system with ATO, I wouldn't think so as long as the amount added is less than the daily evaporation rate, but I would like more input. thanks.
 
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Randy Holmes-Farley

Reef Chemist
Premium Member
Adding baking soda in auto top off should be fine, as long as you are careful to prevent overdosing.

Are you using raw or baked baking soda?
 

natereinhold1

New member
raw, and my ATO is a float valve on my RO\DI. I am wondering if I can use another dosing type in conjunction with the float valve with out changing the salinity as long as i add less freshwater than what the daily evap rate is and the ro/di makes up the rest.
 

Randy Holmes-Farley

Reef Chemist
Premium Member
Yes, as long as it is less via the pump than the daily evaporation, then that is fine. I'd dilute the BS to close to the daily need of evaporation water, so that you need not try to control small volumes.
 

Randy Holmes-Farley

Reef Chemist
Premium Member
If you bake it first, you drive off CO2. That allows it to have a pH raising effect as well as an alkalinity boosting effect. it does not change the alk part of it (except that the volume shrinks a bit so it is a bit more potent on a volume basis). :)

You can bake it at 400 deg F for an hour or so in your home oven, if you want to do that. :)

I show how to use it to make a DIY two part additive here:

An Improved Do-it-Yourself Two-Part Calcium and Alkalinity Supplement System
http://reefkeeping.com/issues/2006-02/rhf/index.php
 

natereinhold1

New member
Now for the 2 part system.... I seldom need to adjust my calcium levels but my alk on the other hand... If I use the 2 part as dosing suggest, won't I end up with really high Calcium levels when both are added equally, due to the fact that I have to add sooo much bs daily? I only need to add Ca about every 6 weeks or so and it is only a little bit.
 

Randy Holmes-Farley

Reef Chemist
Premium Member
If alkalinity is declining and calcium is not, at least over the long term, it is likely because you are using a salt mix with excessively high calcium in it for water changes.

What salt mix?

If that is the case, then using just the alkalinity part unless and until the calcium declines to a lower level is fine.
 

natereinhold1

New member
I use Reef Crystals only. My ph never drops below 8.2. could magnesium depletion have any cause with this(very little decline in CA and alk drops quickly)? I have been waiting for my lfs to get some test kits in, so right now I have no idea what my mag levels are.
 

natereinhold1

New member
The only reason I ask, is that reading briefly on the -when calcium and alkilinty don't balance- it is writen about using a 2 part and calcium rises when alk drops, but i don't use a 2 part(yet) and my calc doesn't rise. And it is all a bit over my head, but seems that magnesium can be a culprit, and i have never added magnesium other than what my water changes do. Is there anything to worry about or just keep adding alk as i have been, or is there something better that i can do?
 

tatuvaaj

Pro-Protozoa
Premium Member
<a href=showthread.php?s=&postid=14771711#post14771711 target=_blank>Originally posted</a> by natereinhold1
Is there anything to worry about or just keep adding alk as i have been, or is there something better that i can do?
Not really, you can add both calcium and alkalinity separately as needed. The reason why they are added together is that by far the largest consumer for both of these is calcification and that uses both calcium and alkalinity in certain ratio.

If you use a salt mix with very high calcium content and you have only modest coral growth it is possible that all you need to add is alkalinity (the "carbonate" in calcium carbonate = coral skeleton).
 

Randy Holmes-Farley

Reef Chemist
Premium Member
Magnesium levels do not appreciably impact the relative consumption of calcium and alkalinity

It is normal for alkalinity to appear to drop "faster", when in reality it usually does not just because there is a huge reservoir of calcium in seawater, but a much smaller pool of alkalinity. So when both are depleted at normal rates, alkalinity drops much faster on a percentage basis and kits often cannot detect the calcium drop until it has dropped a long way.

I discuss that in the first section of this article:

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