To add Dolomite lime or not, advice welcomed!

[RetiredGuy]

Fellow Growers:

I am a little over a month into my White Widow Auto grow. Today was the first day I was able to water fully enough to obtain run-off. Despite always watering at 6.7 to 6.8 pH, the runoff on both plants tested at 5.9 pH.

This is the same thing as I saw during my last grow. Despite numerous flushes I ended up with deficiencies during flower.
I would like to avoid that this time if possible and am considering top dressing with a little lime. Would appreciate your opinions.

I am growing in a 50/50 mix of Fox Farm Ocean Forest/Happy Frog with 30% add’l perlite. I am using pH adjusted RO water with 5 ml/gal ( 150 ppm) cal mag added. The plants received their first feeding at 40% of Fox Farms week 3 grow schedule 3 days ago and are looking good.

I am starting to see pre-flowerss and will be starting blooom nutes soon. Thanks for your advice in advance!

[Going2fast]

Your liquid nutes will lower your pH. You can top dress with some dolomite lime and it will help buffer your water but it should be mixed in at the start. You didn't mention the planter size. For a 5 gallon planter I would go 1/2 cup. Then you can stop using cal mag.