First hydro grow,need advise

So Im trying my first hydro gro DIY trial set up to gain experience ,but need comments and help , as of now I am just over 30 days from seed ,this is just a 2 plant grow , my set up is a 17 gal res feeds 2 5 gal buckets 3/4 pvc supply 12 spray heads per bucket 700gpm pump 110 sec on 8 min off, room temp light on 78-82 f light off 67-72 res temp 68-69 f PH solid 5.9 ,lighting 400w MH 18/6 . osilating fan and good air exchange from exhaust, strain is indica/sativa ,strain calls for a short bushy plant , So I had some trouble with overwatering as seedlings about 1 week in, then worked it out , from there on I have been taking the low feed approch rite now im feeding 300 ppm .5 scale ,Ya I know low. The plants seem to be doing very well as far as looking healthy with good vegitative growth (lots of foliage) PPM level does not really drop maybe 5- 10 per wk by res change. but they are short very short ,roots look good to me Nice white no smell ,I guess the root growth is good also, but I will let you decide and also try to help me .

Bring up your ppms to between 350 - 450. Everything else looks really good. Good job man.

Yea got res change to due , so will be bringing the ppm up to about 390, Just seems to be real short in height and has me Nebie concerned, and trust me thanks for thinking Im doing a good job, but reality is if it was not for this forum ,I would not stand half the chance on growing , Experienced Advise is Worth its weight in BUD Thanks .

It will assist them in getting more of the proper elements they need if you drop the ph slightly,5.6-5.7.

Thanks superstoner, Have a res change today Soo will be bringing the PPM up to about 380-400and will set my Ph for 5.6 -5.7 , I took a look at my PH availabilty chart and I see the band width widen in the 5.6-5.7 range for the elements .iron,boron and copper & Zinc. Again experience Adive is worth its weight in Bud.