Coco coir and perlite

Using coir perlite in grow bags in need of a bit of advice on doing so I’m giving them nutrients daily but only once a day and only one cup per plant any more then that I get runoff and or standing liquid I used more with soil don’t wanna drown my girls

I use 100% coco no perlite. If it is well drained, and it will be in fabric bags, it is impossible to overwater. IMHO, adding perlite just increases the frequency that you WILL need to water. some swear by it

however, be aware; coco should be fed to runoff every time once they are old enough for feeding. It is what flushes excess salts and prevents lockout. 10%-30% recommended every time to avoid having to do a freshwater flush and screwing up cocos internal buffer. otherwise, you will likely have bad things happening right when you are in mid bud when you can least afford problems

The runoff should be removed from the tray under your bags after no more than 15-30 minutes to avoid root rot and drowning your plants. Many people, including myself, use a wet/dry shop vac to remove excess water from the tray. Very quick, efficient, and easy using a vac

Coco is actually technically hydroponic, so you do have to feed it every time once it is out of seedling. It looks like soil, and you can hand water like soil, but that is where the similarity to soil ends. Its hydroponic. as long as you don’t burn them, feed to runoff and clean those trays, you can feed as often as you like with no fear of drowning.

its a VERY cool medium. be aware of the specific nature and properties of coco, and you will really enjoy it


@Precious Which means you’ll be going through your nutrient supply faster than with the same amount of soil, the only downside I’ve found by using coco. BTW, I use 50/50 coco perlite. Keep your pH as close to 5.8 as possible and you’ll do fine. Good luck!

The IKEA solution to collecting runoff without having to move your plants☺


I am two weeks into flower and I am growing with 70/30 Coco/Perlite

@mulch is right on the money! It’s not possible to overwater with coco but it is possible to have sudden problems from not watering/feeding to runoff.

I have two plants outside in a 10 gallon smart pot (fabric). I give them 1 gallon of full strength feed twice a day. It’s likely 30-50% of each gallon ends up as run off but the plants are doing really really well.

I got N problems when I was watering initially like soil (every couple days and just enough to avoid runoff). The runoff also helps to pull oxygen down into the coco for continual airation.

Good luck. I have it on good advice that if I was made of money, I could feed them four times a day but two has caused the main stem to balloon to 3" diameter and the plants are lush (just need them to start flowering).


Ever have a problem with nute burn? I water mine once a day (2 gal pots, I think) with nutes around 60%. Think I could up the nutes and water twice a day? Just about harvest time anyway.

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i think this is a good way to avoid nute burn as you wash away unused salts provided you feed to runoff

the runoff is the key to ensuring you dont end up with too many nutes

i use drip clean, add that to your feed to make double sure those pesky excess salts run off away

i actually just had to double my feeding strength after I started every other day in 7 gal fabric pots. I will tag you in the thread where this is addressed.

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I have not had any nute burn but I did have what seemed like N toxicity when I wasn’t watering to runoff.

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hey wanna thank y’all for the help will change my watering

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I do use drip clean in my indoor gravity fed system but never thought about using with hand watering. Thanks very much.

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it’s hydroponic


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Guess it would depend on how many girls you have

i wish i had the setup and time and nutes to be able to do twice a day, let alone 4. I am doing every other day in 7 gallon pots and they are drinking a gallon during those times, easy. But I am feeding 5 a day (10 total), so as a downside with hand watering coco, it is MUCH more labor intensive than soil or likely even hydro. I am mixing 8 gallons of nutes at a time.

If I stepped up to even once a day… :star_struck:

that being said, the anecdotal evidence is pretty sound. if you feed it multiple times a day, she will respond to it very well and noticeably.


I have these two clones growing in one 10 gallon smart pot.
70/30 coco/perlite (large chunk)

Same mixture in my indoor tent where I have two plants in a scrog. My point is I hate watering and the only plant I hand water is the 10 gallon pot outside.

My tent is set up with the Autopot system (google-able). It has a 12 gallon reservoir (kitchen trash can basically) that is gravity fed to the two pots in the tent. It’s akin to a perpetual bottom feed system with a unique valve that allows for daily “dry periods” in between feedings. It’s new to me but after three months, I love it and it’s fill and go for up to 10 days with 2 plants. I suspect I will have two more and a second reservoir soon!!

My previous divorce likely had something to do with how tied to my grow room I was and the constant watering requirements. No more Brothers and Sisters.


that is 1 of the things i like about coco. the flexibility. we are both using different mixes and techniques and thrilled with it. it’s a good medium. just sayin’

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entering week 5 on the first two girls
staggered them by two weeks two at a time
their looking so so but did very little to them before placing them in flower
their counterparts on the other hand are growing biggie after some super cropping

Great discussion on a topic I was looking for, and bam, here it is, right at the top of the hydro list!

I ordered some coco thinking I might switch from soil, but now that I’ve read all this, I don’t think I’ll have the time to water every day for my big tent. Maybe try it 100% on one or two plants for comparison.

But for the rest, how would coco work as a mix with soil? If I put in, say 50% coco, 25% topsoil/potting mix, and 25% perlite, would that give me most of the rooting and aeration benefits of pure coco with enough soil to allow a cushion of 2-3 days between waterings? Also, with that little soil, and since I’m using more nutes anyway, can I just go ahead and re-use it for a 2nd or maybe even 3rd grow, like with pure coco? Or would the soil ruin the benefits of the coco?

I’m moving soon, and looking forward to building a new grow room, love some of these ideas for auto water systems and lifted pots for drainage! :slight_smile:

without adding perlite, i water every other day, but i am pretty sure i could add a day or 2 to that

i also use fabric pots which dry it quicker

100% coco will likely give you the flexibility that you need, just make sure to feed to significant runoff

as a first time grower, it is a WAY better experience than i expected and that my soil counterparts ever had


try grow bags cloth bags work great allowing more air to the root zone and better drainage


What nutes are you using.
I’m on first grow of coco/perlite approx 70:30.
ATM im just using blood n bone and seasol watering every 4 days to runn off. Though last run off was almost 1700 ppm so perhaps over did it a bit. I also one per week water with just epsom salts. And foliage spray weekly with Seasol.
I have dyna grow bloom for flower.
Im pretty overwhelmed with it all. I have one girl in flower only day 2 and have temp and RH issues at lights off so have tube heater coming and have increased frequency of air exchange
Over night temp drops to 9deg with 80% RH.
Confused AF

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