Yo i push 600ppm but that was in some low ass nute seedling soil. Been busy changing everything and got new grow products to try, bored of weak ass garden shops round here.
Gone totally vegan organic with the Biocanna terra plus soil and using evian to ppm the cal/mag in my water to 200ppm before ferts.
I really only ever gave my seedlings the one dose of ferts and micros just to get them off growing, after that it was a couple of plain water feeds and then i picked the ferts back up when they were bigger and needed it.
With the biocanna terra plus it can start seedlings but is a little strong, they put the ppm of the soil on the back from 800 - 1200 or somthing. Stronger soil than seedling soil. Instead of adding ferts if the seedling soil dont need it i would add a seaweed root drench just to give the trace elements a boost and kickstart the microbes in the soil.
About them white bugs, not saying they are springtail! Got to identify them first but lots of growers get them in soil and they are harmless, very few springtail species eat the roots and even if they do they dont do any noticable damage. They help the soil nutes and spread good funghi and hormones to stimulate the fungal growth. There is a big difference between your pic of some centipede type insect and spring tails. Springtails jump about like mothertruckers a lot, small and run fast for little bugs. Real small too, hard to make out detail, often you might notice there tiny little antenni on their heads.
As for seedlings i hope my soil will be ok for them for seedling, veg and flower. Gone is the seedling soil and small pots, i never seemed to be able to give them enough cal/mag in my soft water area, water ppm is like 40/50 at best, good water but needs to be brought up to 200ppm with cal/mag. I was using epsom salts but without enough calcium to balance the magnesium the seedlings were suffering, leaf twist, dry leaves, spotting etc etc and going quite blue as too much magnesium. I find epsom salts is not what my plants like much and more calcium than magnesium is very important. Dolomite lime helped but never provided very much available calcium or magnesium. We'll see how it turns out, first results are amazing. I just wana grow prefect plants really.
Identify those bugs first dude.
