Your water company on request should be able to give you a complete run down on whats in your water.... i recently fell foul as my water company switched resevoirs.... the new resevoire was 150miles away from the previouse and was lacking in sulphur, iron, boron....

your local aquatics center will be able to test the following

total disolved solids-TDS
PH
PHOSPHATE
GENERAL HARDNESS
CARBONATE HARDNESS(MIX OF MAGNESIUM CARBONATE AND CALCIUM CARBONATE I THINK)
AMMONIA
IRON
MAG
CALCIUM
NITRATE
NITRITE

You can order these straight of the old WWW.

Nutrafin Master Test Kit

peace out

Not if you run the Lucas Formula

Excellent post Delta, I read the whole thing and learned a great deal. I am using Flora series nutrients and R/O water. Flora has a separate Hardwater micro for their hard water. So I am assuming the regular micro has the cal mag i need. I was interested about two thing though:

Mixing tap water and R/O, this would be a great way to get around the ergonomics of my R/O, as it only produces 5 gallons every 1.5 hours and it wastes a lot of water and time in the process.

But more intriguing was the pH discussion. I heard keep it between 5.5 and 6.5 so when I started my seeds yesterday I used 6.34. I'm now wondering if I should attempt to drop the pH.

Could blackstrap mollasses be used at a substitute of cal-mag, it contains a bunch of nutrients such as magnesium calcium and iron