Conductivity budget in RO remineralization

[Sergey]

Hi All,

Let's say you're reconstituting RO/DI water with Seachem Acid and Alkaline buffers and Equilibrium. And you're targeting a conductivity value, of, say 120 uS. How much of that 120 do you allocate to the Acid and Alkaline buffers and how much to Equilibrium?

My example: 5 gallons of RO/DI, I target 120 uS, ph 6.0. I add 0.5 grams of each of the Acid and Alkaline buffers, which brings conductivity to about 80 uS, leaving me 40 uS for Equilibrium.

Thanks,
Sergey.

[DiscusLoverJeff]

Since I use 100% RO water, my TDS is usually 0. So I add RO Right to bring up the TDS to the desired number for what I need it for. Just how much it takes, never really measured in grams but it usually takes 1 teaspoon to get from 0 to 65/75.

Now there is a rumor that people who use RO Right or any other buffers to their water can use Reef Crystal salt in a similar measurement. I have not tried this yet until I get someone to prove that theory.

There is also mention of using calcium chloride and magnesium to get the same results and its cheaper than buying all the other additives like RO Right, just not sure their is proof on that either.

[Sergey]

Thanks, Jeff!

>100% RO water
RO, not RO/DI?

>1 teaspoon to get from 0 to 65/75.
Per what volume of water? It sounds like a 55 gal barrel.

Where do you end up with pH, in the barrel and the tank?

Regards,
Sergey.

[DiscusLoverJeff]

Thanks, Jeff!

>100% RO water
RO, not RO/DI?

>1 teaspoon to get from 0 to 65/75.
Per what volume of water? It sounds like a 55 gal barrel.

Where do you end up with pH, in the barrel and the tank?

Regards,
Sergey.

Sorry about that Sergey,

My water is RO/DI and my holding tanks are 32 gallons each (have 4 right now). My PH is usually around 6.4 but I do not focus much attention on PH as long as I know my RO water does not change. I did measure PH daily but since all conditions are stable and the same day after day, I only rely on my TDS meter to give me accurate (with some degree of variances) numbers for my TDS. It does read PH as well and as I said, it is always the same. If I ever see a change in my discus, I will check all water parameters.

[Sergey]

Thanks again, Jeff! So going back to my original question, in your case almost the entire conductivity budget goes towards, roughly speaking, GH.

My quick experiment with R/O Right got me a pH of IIRC 7.4, that's one of the reasons I'm playing with the Seachem buffers.

Sergey.

[DiscusLoverJeff]

Yes I do spend money on RO Right only. I am surprised though that your PH reading using RO Right is that high? The highest mine ever got was 6.8.

[Sergey]

Jeff, I've finally realized why you keep bringing up money, that's because I used budget in the name of the thread :) I didn't mean budget in the financial sense, but just as an upper limit. That is, if I want to make 120 uS water with Alkaline and Acid buffers and Equilibrium, what part of that 120 uS goes towards the buffers and what part towards Equilibrium, or GH.

Regards,
Sergey.

[mirador]

HI
Regarding the use of calcium chloride etc to modify RO water. That is a planted tank method,is proven and works well. It is so cheap it is free..is handy,reproducuible and does not affect the PH at all. You use calcium chloride (ice melter) for the calcium, magnesium sulfate (epsom salts) for the magnesium, and baking soda for modifying the KH to control PH drop..unless you want a ph drop.There are recipes etc. I use one and it is fine. Naturally,you can,therefore, have high "solids" or TDS but also have low PH.

[Sergey]

Hi mirador,

Can you share your doses of CaCl, etc.? I'm trying to figure out what portion of the target TDS should be from Ca and Mg salts, and what portion from pH control agents, like baking soda.

Regards,
Sergey.