[Dr. J]

I sprouted some seeds and they’re about 2-3 weeks old. I put them from rock wool cubes to 70% coco 30% perlite (royal gold coco). I never have flushed my coco before putting clones in, but I don’t have to much experience with seedlings and coco and noticed the run off was around 1800 and I have been feeding them tap water that’s 280 ppm .5 scale phd to 6.0. Some shriveled up and others are looking nitrogen Defeciant. Should I be worrying about the run off or do they need food?

[WHIPEDMEAT]

Anything over 10 PPM and you should invest in a reverse osmosis system,
seedlings do not have the ability to take over highly salted media, those 2 are or basically should be inert without nutrients but coco can be dirty....... you need to flush it before usage or you can simply go with perlite with more frequent irrigation, with low Ec ~0.6 mS

better switch your instrument to measure Ec,

[MJPassion]

Originally Posted by WHIPEDMEAT

Anything over 10 PPM and you should invest in a reverse osmosis system,
seedlings do not have the ability to take over highly salted media, those 2 are or basically should be inert without nutrients but coco can be dirty....... you need to flush it before usage or you can simply go with perlite with more frequent irrigation, with low Ec ~0.6 mS

better switch your instrument to measure Ec,

Are you sure about what you say here?

My experience is much different!

I mean... your good on the coco advice but that number... man I’d be ecstatic if my tap water were 10ppm.

@Dr J, find & follow a coco flush regimen. There are many threads that address it. I’m not a coco person so can’t say more.

[WHIPEDMEAT]

i am sure.
it is a type of hydroponic setup and you need almost pure water to do it properly, specially for seedlings their roots are very sensible. and lower the ppm or Ec of your water, more nutrient can be added with lower Ec or ppm before it hurts to them.
less is more sometimes with nutrients

[OG_NoMan]

I run coco dtw. Now i am no pro or anything so take what i say for what you will. My house tap is 450ppm and i had two complete runs using this base water and gh micro for hardwater. I flushed alot and wasted alot but it grew bud. This year i have installed ro and it comes out @30 ppm. I currently mix 1 3/4 gallons ro to 1 1/4 gallons strait tap for a 200ppm starting water and mix from there with little issue. With this mix i am able to run with minimal to no run off. I use roots coco palms and basically water the pots for 2 days before planting/transplanting basically flushing and putting the nutrients i want to be available. IMO your biggest issue will be cal/mag lock out for which you will have to flush. It is a pain in the ass to grow with hard water but it can be done. Good luck and read as much as you can.

[Mikell]

Seedlings can handle a lot, I plant in 1.2EC flushed coir, but you're roughly three times that concentration.

Try to reduce your starting water below 0.2EC and feed 0.6-0.8EC (tap + feed) for a week before rising to 1.2EC.

[WHIPEDMEAT]

a lot ? what you described to him is not a lot it s optimal. and give the seedlings unwashed coco, high Ec tapwater and that is called lot. they cannot thrive in it, ofc they handle it still alive, heh ? xD

[beta]

Don't ever ever ever ever ever feed plain water to coco, it will clear the cation bank and deprive your plants of calcium and magnesium for weeks.

'Flush' your coco with regular full strength nutrient solution. I've never met a strain no matter how picky that can't handle 1.4EC from freshly rooted clone onward. Feed 1.4EC every single time you water and things will be fine.

Don't worry about your tap water unless it's known to be nasty. I'm not sure what the dude claiming over 10ppm is bad is saying. Mine is 0.4EC (200ppm @ 500 scale) out of the tap and it works great.

[Mikell]

Originally Posted by WHIPEDMEAT

a lot ? what you described to him is not a lot it s optimal. and give the seedlings unwashed coco, high Ec tapwater and that is called lot. they cannot thrive in it, ofc they handle it still alive, heh ? xD

What I mean is there is no need to baby seedlings, especially in coir. I am speaking of some peoples habit of avoiding food until true leaves form, which I assume is why he hasn't fed them.

[WHIPEDMEAT]

sorry than, that's a really bad habit in my opinion too,
usually i do these steps,
germination on pure perlite bed with rain or distillled water, than seedlings transplanted into a very light mix of perlite, coco coir, optionally vermiculite, and i like to add into this a few spoon of ghe mineral magic, it contains silica and some other minerals, but from this step they are on fed with a light nutrient Ec 0.6-0.8 as you said and increased in few days over 1