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sneeyatch
09/23/2011, 02:14 PM
I'm struggling to keep my alk up where I want it. It's OK, but it's coming in at the upper 6's / low 7's. I want to use Randy's alk recipe (baked baking soda recipe) to help get me where I need to be. My question is, can I mix up the solution according to the directions and dilute it into my 10 gallon ATO container and let the ATO dose the solution? I'm thinking it may be too concentrated of a dose to allow the ATO to take care of it for me. I'm not opposed to manual dosing, but if I can let my equipment do it for me, then I would.

BTW - the tank is a 150 gallon deep dimension and I lose maybe around 2 gallons a day in evaporation - that's why I was wondering if it would be too much of a dose to the system since Randy's recipe is pretty strong.

Any help or advice is appreciated.

HighlandReefer
09/23/2011, 02:43 PM
Per this link:

http://photo.net/black-and-white-photo-film-processing-forum/008y6d

"A 10.6% solution should have a pH of about 11.6 according to CRC Handbook."

This is refering to sodium carbonate (baked baking soda).

So, diluting the sodium carbonate does not reduce pH all that much, it is still high and overdosing can cause local high pH levels and precipitation. ;)

I would hook a dosing pump on a timer to your top off system (perhaps a float switch), which is going to be the safest way. :)

If you don't have low tank pH problems than using baking soda (sodium bicarbonate) would most likely be fine, since it does not raise pH. Usually it is recommended to not increase you alk level by more than 2 dKH per dose.

sneeyatch
09/23/2011, 02:57 PM
Usually it is recommended to not increase you alk level by more than 2 dKH per dose.

That's my main concern. I'm worried that if I make up the dosage amount as per the directions, and add it to my ATO reservoir, that it would potentially overdose the system based on it's evaporation rate throughout the day.

My pH tends to be on the lower side as well, but acceptable so I'd like to benefit from this as well.

I've tried kalk in the past, but demands are too high for kalk to keep up.

HighlandReefer
09/23/2011, 03:19 PM
For low pH problems I would max out the use of satured kalk water first and then supplement the rest with two part using sodium carbonate as your alk supplement. Satured kalk water will provided about twice the pH increase that sodium carbonate (baked baking soda) will. You may be able to dose the two part by hand if it is not much. If too much, I would use sodium bicarbonate (regular baking soda for the rest).

HighlandReefer
09/23/2011, 03:22 PM
Either way you go (kalk or sodium carbonate) you do need safe guards to prevent the pH from rising too high if overdose should occur. ;)

sneeyatch
09/23/2011, 03:22 PM
Gotcha - thanks Cliff.

HighlandReefer
09/23/2011, 03:22 PM
You're welcome. ;)

sneeyatch
09/23/2011, 03:25 PM
I was actually dosing kalk with my topoff for a while, but after it couldn't keep up with the demand, I switched to a manual dosing method with typical RO/DI water for top-off. I'll re-think my strategy.

I appreciate the help.

HighlandReefer
09/23/2011, 03:35 PM
The amount of alk and calcium kalk water can supply will depend on your evaporation rate.

With a total water volume of 150 gallons and an evaporation rate of 2 gallons per day you will be able to add about 1.5 dKH of alk per day. The rest will need to be supplemented with two-part. ;)

If you want to try what I do and add vinegar to your kalk mix than you can boost the alk you can add daily to about 2 dKH per day.

If you increase your evaporation rate using fans &/or more water surface area you can also get more alk out of kalk water.

For example if you increase your evaporation rate by 1/2 gallon more you could almost get 2 dKH of alk per day.

sneeyatch
09/23/2011, 06:43 PM
I didn't think about using fans to increase the evaporation rate. I started topping off with kalk this evening and I'll see where it goes over the next few days / week.