Couple questions

Unsure on a couple of things & was hoping I could get some clarification. Just made jump to coco for first time. Seeds started in solocup/promix, were hurting/slow growth but as soon as i got them into new 3gl homes of coco/perlite & started feeding canna w/ their “light feed” recommendation things have been great just taking off. But here’s the thing, I’m new to these meters & thought my reading of say 800 on my HM tds-3 meant .8 E.C.... is this correct? Or am I actually feeding @ 1.6 E.C. if my meter reads 800... & if I am, should I correct it? Im new to this & idk if I’m going to run into toxicity probs at these levels?...so if canna light feed recommends say 0.9 E.C. my meter needs to read 450? I’m feeding close to double but the plants look like they really like im just worried I’m gonna run into some toxicity problem soon doing that? just wondering what the community thinks.
TYIA

.9 EC would be 450 on that pen. Sounds like plenty for regular feedings in coco which I assume you are doing often? If you're double that you will run into toxic salts buildup eventually I'm pretty sure tho I don't grow in coco. I mainly use peat based ProMix HP where I water every few days once it's dried out.

The HM pen you are using should be 0.5 scale.

Awesome ty for the reply that’s what I was thinking, Ive been Overfeeding since I learned about this damn conversion table...theyve been getting too much ..it’s just weird, because I follow their chart mixing for their “light feeding” & it still comes out that high...& they’re doing well since the transplant lol so hesitant to change but if I’m gonna get build up then ya I don’t want that... as for ‘feed often’ they’re being fed once every other day w/ runoff only @ the inside of the 3gal where the roots are... transplant from solos few days ago so I’m under assumption I should do this until roots fill the pot...still get good runoff just not from soaking whole pot if that makes sense. I’m thinking this week go to 1x a day & progressively widen the feed circle, till I reach whole pot, then 2x whole pot etc

You're not soaking the whole pot? Coco should have multiple feedings per day so it's always soaked. Best method is drain to waste for coco where it's always getting runoff and never gets dry even a little bit. That's one reason I'd never get into coco. Another reason is it's expensive as hell compared to ProMix and not available locally like ProMix is.

You should read up some of the posts in the forums about the care and feeding of plants in coco. Even in dirt you always soak the whole pot but if feeding nutes you use higher ppm less often. Growing in coco is like hydro in many ways as is growing in a soilless media like ProMix HP or any other soilless mix. The media is just a place for the roots to grow and the plants eat what you feed them. That's the tricky part is feeding the right amount and there is so much to know about how to do that right with so many variables books are written about it.

Have some free books.

I found a great spot to download FREE POT BOOKS . I downloaded a grow bible first and got lots more. Books look great and complete like the real ones I have here. No web site but just a page of links. Just right click on what you want and then "Save Link As" to download so they don't open first as many are 50+ megs. They got lots. Enjoy.

I figure the roots are mainly centered in the promix atm...only a couple day since transplant...the solution I pour if I soak the whole pot will build up in the rest of the cocoon because the roots wont be absorbing it since they’re not there...that’s why I’m not soaking whole pot...am I wrong to do this and I should soak whole pot even if just transplanted?

Coco* not cocoon lol

KeyLimeRye said:

I figure the roots are mainly centered in the promix atm...only a couple day since transplant...the solution I pour if I soak the whole pot will build up in the rest of the cocoon because the roots wont be absorbing it since they’re not there...that’s why I’m not soaking whole pot...am I wrong to do this and I should soak whole pot even if just transplanted?

Click to expand...

Yes you need to soak the whole pot or at least that's the way I've always done it in ProMix and I'm pretty sure you need to that in coco too. I usually start clones or seedlings in tiny 9-hole seedling pots then go to a 2L pot then a 4gal pot and always soak the new pot good at transplant time. I won't feed every time tho for the same reason. The roots haven't filled the pot yet so areas they haven't grown are still holding nutes. I'll use just water for maybe the first few waterings so may not feed for a month after moving a relatively small plant to a large pot.

With the ProMix I rarely get any runoff so when the plant is small the bottom half may still be wet while I can dig down a few inches and it's dry tho moisture wicks up from below. This is where guys run into root rot problems. That moist bottom has no oxygen in it and bad bacteria can take over and get rot started. Even going from a 2L to a 4gal pot I generally have roots poking out the drain holes in 5 days or so. A 2" plant can have a foot long root so most peeps water again when the top inch or so is dry when the plant has roots down in the wet area already. If you just water a little at a time then the roots end up hitting dry media and dying. It's like root pruning when you don't want it to.

You are correct in saying that nutes will build up in the pots if you feed all the time without substantial runoff to flush out the old stuff. Same thing happens with high ppm tap water. Most of the minerals in the water add up and create toxic conditions in the pots. That helps lead up to toxic salts buildup that I see so often in the forums and with my own plants tho I use RO water only. We have low RH here so the plants drink a lot more and pull up more minerals than they can process so it builds up in the leaves and usually shows up about mid-flower with older leaves going all brown/yellow all over and turning crispy. That can work it's way up to the buds eventually and once started can't be stopped even with heavy flushing tho flushing will slow the progress.

Like I said, you should search the forums for more info about coco as I tried it once almost 20 years ago and didn't like it but I was doing it all wrong with crappy coco that surely needed to be rinsed well before use but I knew nothing about it at the time. Cheap shit that came in a hard block and was likely loaded with salt. Wasn't even a label on the block I bought just a felt marker saying 2kg coco coir. Still have half of it around here somewhere and should try rinsing some then check the ppm of the water.

Ya I’ve read so much already but there’s always something else I find out the next day that I wish I found out yesterday & been reading so much... now i just don’t know if I should flush or not, the tips aren’t burned or anything like I’ve seen w/ excessive nutes... but perhaps in coco that doesn’t matter & it’s building up to dangerous levels regardless that will soon show itself? ...idk this is my inexperience showing...I read to always water w/ Nutes never just plain water w/ coco, so I’m thinking I should try and do like a mild flush w/ maybe 1/4 the strength they’ve been getting? Do that a couple of days for their watering and I should be good? My thinking/hope anyway lol

Got any decent pics? No blurple ones please.

Flushing it through with 1/4 strength nutes would probably be a good idea then feed that daily with a good runoff as well to keep them happy.

I've seen a lot of posts by coco growers saying multiple waterings per day are what's needed so they usually have a timer controlled rez set up to do that. I sure don't want to be bothered doing that so I'm sticking to peat based media or getting back into DWC where I can double or triple my yields and not have to muck around with media at all. Tried organics and do not do well with that. Soilless with hydro nutes works better but still doesn't yield like DWC did. I've done about 50 DWC grows since 2001 and always had great results. It seems to be the easiest and most productive for me and when you see plants growing 3"/day in veg it's amazing.

Nah no pics unfortunately but ya I think I’m in for it haha. Now that I’m looking, some of the leaves and especially the newer growth, has this metallic looking sheen to it which instantly made me think zinc for whatever reason. I looked up zinc toxicity and it’s not exact but does look similar lol


That 1st pic, the big leaf @ bottom under the phrase “es turn yell” ....looks pretty close but they’re not yellow like that, just lime green w/ a metallic like sheen & dark around edges...& that lime green metallic doesn’t extend to the outer part of leaf like the yellow does in that pic either...it’s localized to the center of leaf idk...some of the edges on darker (older) leaves have metallic sheen around their edges too lol

I always wanted to get into DWC too I may someday I imagine, reading about the slime turned me in a diff direction tho... from what I gathered thought they’d b hard to manage... but now this coco is so guess they all have their challenges

I grind up a couple of my zinc tables to give the plants a couple times each grow. Also iron, B-1, selenium, vit. C and some citric acid.

Low zinc being the cause of problems is super rare. Manganese, boron or iron are more likely to be the culprits in a micro-nutrient deficiency but when the PH gets too high all sorts of nutrient lockouts and problems can appear. Most people just toss more of what they think the plant needs in there and end up making things worse. Can take some real detective work to ferret out the root cause for plant issues and most of the time it's pH related when you know the plant is getting enough nutrients either in a good organic soil or bottle fed babies.

This a great chart for using it's clues to figure out what's going on so copy this to your device for later reference.

I was referring to toxicity since I’ve been feeding like 750-900 ppm or 1.5-1.8 E.C.... in early veg which I’m now aware of lol. Thought you might appreciate an update tho, I mixed solution a lil lower to like 630 ppm today or 1.3 ish E.C....tested initial runoff which read 111 x 10 on my meter so over 1100 ppm or 2.2 EC lol...I’ve read in coco that runoff EC should b about 300 ppm more than the inflow of the nute solution. If it’s over 400 ppm more than the inflow then I should flush per cocoforcannabis.com...however I can’t rememver where, but I also remember reading something about taking the reading of the runoff 20 mins later after pouring more solution through & not taking the initial runoff....which I’m hoping is the case because i waited a bit and watered in the same amount of solution again....& this time got a reading of Ppm’s in the 900’s which I’m under the assumption is perfect if I’m feeding around 6-700 ppms...idk, anyone w/ experience in coco I welcome the advice lol