1 lets start from a known:thumbsup:
Get some full service , full service 40 watt cool white bulbs
2 The starting ppm of you water
Now add , starting at 400 over the water you have:thumbsup:
3 What does the plant say:Tomcat::thumbsup:
You want about 1/16-1/8 leaf tip burn, to maximize groth
4 Ph should be around 6.0 to 5.4 for maximize plant up take
I have used 1300 ppm for years with a 600 (yea tape watre) (There tons of micro chem' , from iron, copper, etc in normal tape water
It takes about 3 days for a plant to tell you what it needs. Watch you plants, and they will tell you.
AND THE RULE OF THUMB IF SOMETHING GOES WRONG FLUSH THE HELL OUT OF THEM
One more note the larger the res, the more stabel it is , and alway go slow when adding chem, ferts.
And once your plants get to 1/3 - 1/2 the max height convert to Warm White bulbs.
Put them CPL to good use in the trash, or closet where the boogie man hides.
Note I use Cool white 38 watts till they get to 30-36 in hight in 1/2 gallon pots.