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View Full Version : Yes, 2-part finally maintaining targets!


LouH
03/16/2012, 07:31 AM
After months of adjustments, getting help from this forum, and at times on the verge of tears, I've finally gotten 2-part to maintain target levels of Ca=425 and dKH=9.

I was trying to dose Recipe 1 to keep pH up, and had exhausted every conceivable means of hitting target levels without fusing all of the GAC in my reactor into an impenetrable mass and turning my GRO into white beads. The way that I did this was to simply change over to recipe 2, which is what Randy suggested months ago.:rolleyes: My hesitation to chance recipes was due to the fact that I wanted the higher pH, I feared that my pH would drop lower than what I wanted, and I bought a 5 gallon bulk container of sodium carbonate from BRS.

I run an Apex controller, and looking at my pH graph from the last 24 hours, my pH high was 8.15, and right now it is 8.09. That's a pretty small day to night fluctuation, and the pH is in range.

My next question is what to do with all of that sodium carbonate that I have? Can I mix it with sodium bicarbonate in some ratio such that the pH of the mixture is in the range of 8.2-8.3 and adjust the dosing rates of both components (I assume the dosing rates will no longer be balanced, although I could probably adjust the Ca solution also so that the 2-parts are 1:1 on a volume:volume basis)? Right now I'm dosing the Ca component of the 2-part at 1/2 the rate as the alk component because I had 3 gallons of the Recipe 1 Ca component already mixed when I made the alk component change. This dosing regimen is working just fine. For the record, I'm dosing 350 ml/day of recipe 2.

Finally, I want to thank Randy, Bertoni and many others for offering their guidance and opinions in an attempt to help me meet this goal. I can finally move past this chapter and start enjoying my tank again. :beer:

Lou

bertoni
03/16/2012, 01:16 PM
You could add a bit of the sodium carbonate to the bicarbonate, maybe a ratio of 9:1, mostly bicarbonate. That's likely safe enough. You can replace 1 tsp of sodium carbonate with 0.9 tsp of sodium carbonate. So the ratio is fairly close to 1:1, at least if I've done the math properly.

LouH
03/16/2012, 07:25 PM
Bertoni,

On a mass basis, are you saying that I would take the total mass of the alk portion of recipe 2 (297g), subtract 10% (29.7g), and add 29.7g of sodium carbonate?

Lou

bertoni
03/16/2012, 09:09 PM
I was working on volume, not mass. I'd probably use 1 cup of sodium bicarbonate and 5.5 tsp of the sodium carbonate per gallon of water. It's almost 1:1 by volume, really.

LouH
03/17/2012, 08:26 AM
Got it. Thanks Bertoni.

What would my Ca solution look like? How much CaCl/gal?

LouH
03/17/2012, 08:39 AM
Sorry Bertoni, still waking up. The Ca would be the same as the Recipe 2 component.

bertoni
03/17/2012, 01:56 PM
Yep. :)