Part 2 of recipe one precipitating out.

[BIGGUN]

My part 2 of recipe 1 is settling out in a crusty brittle substance on the bottom of my milk jug.

I mixed 2 1/4 cups of baking soda (baked at 325 for at least an hour) with ro/di in a gallon milk jug. It would not totally dissolve easily so I microwaved it until it did. It wasn't boiling but it was probably heated to around 180 degrees. After that I let it cool to see if anything dropped out.......it didn't. that was two days ago, today I got the jug to dose with and there was a 1/2" of fluffy brittle precipitation on the bottom.

What did I do wrong?
Is this normal?
How do I fix this if it needs fixed?

Thanks,
Kevin

[gtrestoration]

I have had the same thing happen in the past, only with the "store bought" version. It would happen nearly every bottle. I always thought is has contamination from something like mixing up the caps. It also happened with the first gallon of Randy's recipe.

I've since started dosing with a Litermeter lll and mixing 4 gallons at a time, dosing from a 5 gallon bucket. There's about a gallon left and it has yet to happen in this situation. So the contamination reasoning may be correct or just the action of pouring to measure and introducing air (co2?) into it maybe?

If it's forming solids it must be less potent, not unsafe to use, just not balanced with the calcium part. If it were me, I'd just try heating it again. At worst it could only get worse and you'd have to buy another box of baking soda.

Steve U

[Randy Holmes-Farley]

How much material are you talking about? A little bit of solids there is not a concern.

If a significant amount preciptiates, then either there is some contamination present in the baking soda, in the water used (calcium would be a problem there; did you use RO/DI water?), or the baking was not complete (unbaked baking soda is less soluble).

Try baking longer next time, and if it still doesn't dissolve, just make the whole thing more dilute (both parts).

The 2 1/4 cups was before baking, right?

[BIGGUN]

Randy,
2 1/4 cups before baking, Baked at over 300 for well over an hour, dissolved it in heated ro/di water. It all mixed in at first then the second day there was about a 1/2" of transluecent, brittle, fluffy(lack of a better word) material on the bottom. Since the 2nd day nothing else has settled out and adding 50 ml of each seems to be working for my system.

My Ca is staying at 425 and my Alk is staying at 10~11 dKH.

I guess I'll keep using it since it's working, just wanted to know what I did wrong. I'm guessing since everything appears to be in balance I must have added more than the 2 1/4 cups to start with and the excess just precipitated out.

Sound reasonable?

Thanks,
Kevin

[Randy Holmes-Farley]

Yes, that sounds like a fine plan. :)

[Mimbler1]

Next time you make up a batch, you might try baking for two hours. I did this on my last batch, and it dissolved much easier. It could have been coincidence, but I intend to continue using two hours in the future,
Mike

[Randy Holmes-Farley]

Yes, if it isn't fully converted into Na2CO3, then it will dissolve more poorly. So that is a good idea. :)