I use recipe #2....my ph is low...7.6- 7.9, but I dont do recipe #1 because I feel the PH swing I get when I dose recipe #1 is more harmful then having a slightly lower stable PH....

For those with low pH, and if your alkalinity readings are good, then you most likely have a problem with the air exchange at the waters surface.
Either there is not enough turbulance at the surface or, the more likely cause is too much CO2 in the household air.
To see if this is the problem, take a sample of water and check the pH.
Then, aerate the sample outdoors for about an hour or two.
Recheck the pH, and if the pH is now higher even by a little bit in that short time, then you have a CO2 problem.
This problem is common in households that are shut up for winter heating or for summer air conditioning.

I use recipe #2 because I top off with Kalk.

My system is approx 500G.
I mix 3 Costco boxes into 5G of RODI. Each box is 2 cups or 500 ml. I then dose this on my ProfiLux Doser at 48 ml per dose at 20 times a day. The 5G mix will last approx 1 month.

My PH is steady at 8.24

and

My ALK is steady at 8.30 DKH

I sometimes bake the Baking Soda but most of the time I don't. I have not noticed a change in either the PH or the ALK.

When I bake the Baking Soda I take 2 cookie sheets and put 3 boxes or six cup on each sheet. I then bake at 300 degrees for 60 minutes. I then seal it in a plastic bag and store it in a Tupperwear container until needed. I have not had any problems with this and my consistency of both PH and ALK have never been more consistent.

Tom R

Thanks Tom. Yeah, I think my issue has been that I only bake enough to make one batch, which used to be good enough for 1 month, but is nowadays is closer to more like a week. Making more than needed and storing the excess makes a lot of sense.

I think my first order of business is switching to larger reservoirs.

For those that manually dose what do you use? Jug with pump into a measured cup?

I just use 4 litre jugs and siphon the limewater into the sumps using 3/16" airline tubing.

In my old tank I always struggled to keep my PH up so I used to use recipe one and also prebaked large amounts to store but now in my present system I use recipe #2. For whatever reason I don't need to increase the PH and it's so easy. I keep my alk mix in an 18 gallon tank and just top it up every few weeks with R/O & Arm&Hammer. I also have a heater & powerhead in the storage tank to help keep it in solution.

Also when I dosed manually I just used 3(ca, alk, mg) cups with pin holes at the bottom sitting on an eggcrate shelf I laid across the sump and poured the solutions into them for a slow drip. They needed regular cleaning to unclog them but for a ghetto DIY it worked fine.

I use those Blue 5G water tanks used for camping availble at Canadian Tire.

I use hard 1/4" tubing from the jugs to the ProfiLux doser and soft 1/4" from the jugs to the sump.

Tom