Few questions about DWC

I've been fuckin around with bagseed in a 21 gallon rubbermaid tote dwc with five 2.5" net pots and miracle grow all-purpose. I'm feeling fairly confident and knowledgeable enough that just ordered some real beans, although I will be taking this bagseed to harvest before the real shit is started. I've been using dwc, FIM, and cloning techniques on this grow, as well as responding to some interesting problems (like recovering from a day in a 103* dumpster... don't ask) so I'm getting lots of practice.

I want to get real nutes before I 12/12, and also learn how much I need to feed. Seems like AN 3 part nutes and a couple additives for flower are the big shit around here, so I will prob give them a shot. What I don't know is what the PPM of the res water should be at various stages of veg/flowering. I'm guessing I wait until seedlings have their first set of 3 finger leaves, then start 1/4 strength feeding. So if 1200 PPM is full blown flowering nute levels for my strain/setup (just a guess), then I should keep seedlings at 300 PPM, and gradually increase the PPM as the plant vegetates... but to what levels? I guess I need to learn about feeding schedules basically.

For my nute water, I fill up with 20 gallons of water from the bath tub, and use Top Fin aquarium water treatment which claims to dechlorify, and neutralize toxic heavy metals and says nothing about enhancing fish slime coat... however I have no way to test this so I just have to assume it works fine (if it's good enough for fish, hopefully good enough for plants). Then I do 1/4 strength MG and add some sodium bisulphate ph down for spas and test with litmus paper.

I'm not sure how often to water the net pots. My rockwool never seems to dry out, but I water them anyway twice a week or so. Sometimes I use plain water, sometimes nute water. Sometimes I spray the top and bottom of the leaves with plain water. Could use a little more knowledge on watering.

Can anyone recommend a PPM tester for less than $40 or $50?

Miracle Gro in DWC? Umm no. Use a hydroponic based nute liks GH or Dynagro if you're on the cheap. If you have cash flow there are many hydroponic nutrients you can chose from with many claims, hype, and some erroneous information thrown in. Enjoy the hobby.


I keep my net pots with water at bottom, never top feed they do fine. As long as medium in netpot is moist.

BigBuddahCheese said:

Miracle Gro in DWC? Umm no.

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I agree and everything... but I mean, I had to have something to get started, they weren't just gonna grow in water.

Use a hydroponic based nute liks GH or Dynagro if you're on the cheap. If you have cash flow there are many hydroponic nutrients you can chose from with many claims, hype, and some erroneous information thrown in. Enjoy the hobby.


I keep my net pots with water at bottom, never top feed they do fine. As long as medium in netpot is moist.

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Thanks, I'm going to the hydro shop today.

Malevolence said:

I agree and everything... but I mean, I had to have something to get started, they weren't just gonna grow in water.

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Thanks, I'm going to the hydro shop today.

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Yes they will grow in just plain water until about 2 to three sets of true leaves you be amazed how much they can grow without nutes added.

Either way I would start with proper nutes and get off to a good base, then use a non-hydro based product that will probably do more harm then good, your plants as is probably grew on mostly H202 anyway because doubt that is water soluble to absorb.

I was using the MG all-purpose plant food. It's a water-soluble blue powder made for watering cans... not the little time release balls for soil. Originally I was scared of nuteburn, and wasn't feeding... the one in the back ended up wilting and almost dying from a (I believe) lack of nutes. That's why if you look closely you can see I pruned the lower fan leaves because they were over 50% dead. Once I transplanted to the dwc and started feeding the MG, they flourished almost immediately.

I went to the hydro store and got a bottle of GH FloraNova Grow, and Hanna Primo PPM meter. My MG nutes are at 530 PPM which is pretty spot on I believe for clones/seedlings... could be a bit lower maybe but I'm about to change the res and use these gh nutes anyway.

Right on.. I am just saying that a good hydro based nute from your local shop like GH, DYNA, Fox etc will more benefit your time. I know we all are excited to get it going, but dont waste your time with negro rigged nutes and tools, you're setting up to fail no matter how promising it starts or never does.

PH, PPM pens (not solution testers) are a must. Good low EC water is also a must <100. Your water is your soil in DWC so make sure its properly setup for roots like you would with dirt. Also 70F or lower for water temps.. its a lot to take in, but if its not managed your plant will or is suffering.

I changed my res... my tap water is 150ppm and there's not much I can do about that. The nute solution is 355ppm so I'm at about 205ppm of nutes; that should be pretty good for clones. For temps, I put a fresh gallon jug of ice in the res every 12 hours which keeps it around 72* F I want to get it lower, but 2 gallons of ice drop it to 52*. So I'll prob use 2 liters or something.

How is superthrive used in DWC? I know not to use it for flower unless I have an emergency, but right now I have about 50 drops in a 20 gallon res with 4 three-day-old clones and 1 seedling. I soaked the rockwool and dipped the clones in a superthrive/MG solution when I took clones. And using a diluted amount in the res for veg... is this alright?

good question..don't use superthrive myself..but I am a DWC dude. Listen to BuddahCheese...whomever that is..they gots skillz