k2co3 - a question

2176 Views 11 Replies 5 Participants Last post by  fplata
Folks,

if i where to mix K2CO3 with 500ML RODI water and i wanted to get a concentration of 3.4 PPM per 1ml squirt into 20l of water, how many grams of dry K2c03 would i need?
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I have heard some problems using potassium carbonate (K2CO3). Use potassium bicarbonate (KHCO3). I do not know how much to use, though. Probably very little.

1.5g NaHCO3 in 25 litres of water = 2 dKH
1.8g KHCO3 in 25 litres of water = 2 dKH
1.2g K2CO3 in 25 litres of water = 2 dKH

Taken from http://www.theplantedtank.co.uk/RO.htm

Hope this helps,
John
Hi fplata,

It's been a while since I did ppm.

0.12 grams of K2CO3 will increase the K in 20 liters 3.39ppm

Therefore 0.12 grams X 500 (60 grams) of K2CO3 in 500 ml of water will raise the K2 0.12 grams or 3.39ppm per ml. in 20 liters of water

I do not know if you can dissolve that much K2CO3 in 500 ml of water but that is what it would take if my calculations are correct.
Hi fplata,

It's been a while since I did ppm.

0.12 grams of K2CO3 will increase the K in 20 liters 3.39ppm

Therefore 0.12 grams X 500 (60 grams) of K2CO3 in 500 ml of water will raise the K2 0.12 grams or 3.39ppm per ml. in 20 liters of water

I do not know if you can dissolve that much K2CO3 in 500 ml of water but that is what it would take if my calculations are correct.
How did you find out that .12 grams of K2CO3 increases the K in 20 L to 3.39 PPM, i had a similar number to you, i came up with 70 grams, but my math was complicated. i know the amount of K2SO4 required, i then found out the mole weight of both compounds, derived the mole weight of K on each of the compounds based on the percentage and then did the math from there, I know there has to be an easier method as mine is very probe to lots of error. Thank you again
Hi fplata,

I would like to tell you I had it memorized, or I just did the numbers in my head, but I used the Fertilator.....a handy tool to know about!
Thank you sir awesome tool
Hi fplata,

That is what this forum is about, sharing information and helping each other become more knowledgeable about our hobby and enjoy it more.....I was glad I could help!
I see you are trying to make ADA Brighty K am I right? Consider using KHCO3 instead of K2CO3, it will raise your hardness a little more but is way more safe K2CO3 is more alkaline and might raise your pH fast.
And you are 100% correct, thank you for the input. Now I need to figure out the amounts for khco3. Back to the drawing board
Not to hard to figure out, the g/mol weight of k in both compounds is very close @ 40g and 41g so the formula should be very close, and due to the error for impurities I will use 60 grams of khco3 diluted in 500ml if water to get the concentration I want.
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