Math help?

[Craigdillman]

Ok brain is tired reverting to help on this one, 150 gallon total water, trying to raise calcium and alk back up into normal ranges with 2 part and start running Kalk (this should meet the demands of my tank so far) (long story mag dropped down and started burring through calc and alk)


so..

Trying to raise 150g

Using bulk soda ash (sodium carbonate) how much is needed to raise my tank by
0.5dkh (gonna raise it slowly over a week)

Thanks lol
Cheers
Craig