So I am going to grow in a 3x3 grow tent using a 400w hps light. (already have the light, do not yet have the tent). I happen to have an Emily's Garden but decided its too small so I am building something similar with an 18 gal rubber maid container. So the plan is to cut about 4 holes in the lid for plants, get a pump, and a couple air stones, and go soilless. I understand how it all works, and my plans are coming together. but I have a few questions. Once its all done, and you fill it with your water and nutes, and the lid goes on, and the plants go in and begin to drink up the water, then what. How low do you let the level get to before adding more. Also, do you only add water the next time, and no nute? I am sure I don't want to be adding nuted water everytime I raise the level right? I would assume it would get way over nuted if I did that. And how many times do you just add to the level before you flush it out and start fresh? I guess what I am asking is once its full and gets started, how do you tend to your water and nutes from there on out? And about flushing. Once my roots go through the net pots and down into the water, what is the mest method for flushing. Once 3 plants have a root system going I do not imagine lifting them out is an option. So what do you do to flush? And one final question. My plan is to germinate in paper towels, then into presoaked rockwool cubes. And then the cubes into their final net pot filled with soilless medium. I want to have 3 or 4 at the most holes in the lid of my 18 gal bin. How wide of a netpot should I get considering it will be the final place for the plant to grow? 6" pots? Thanks in advance.
When your plants are small you wont have to add water. Every week I empty my 5gal bucket and refill it with a new batch of nutrient water. Once they are a bit bigger you will notice over that week the water level drop, add clean distilled water to raise the level back up. Your right, topping your res off with more nutrient water will eventually raise your PPM like crazy. In full flower my plants can drink up to 1gal per day if not more, so im constantly adding fresh water to them. I still only add new nutes once a week when I empty and clean my buckets.
Not to hijack your thread, but I'm wondering something similar here (and I noticed some of your questions still haven't been addressed so this should bump the thread as well). I'm planning to build a DIY bubbleponics similar to Stealth Hydro's. I've seen pictures of the roots in those setups and they look like they get all tangled up together. Is it possible to take out a net pot and move it to another, identical setup in a different cabinet for flowering? Is it okay to cut some of the roots where they tangle? Is it okay for the roots to dangle into the water? What is the protocol for unwieldy roots?
It's important to keep your res topped up with fresh water , As plant drink they tend to drink more water than nutes , so your Ph will drop exponentially as your water level goes down. There a 2 specific reservoir maintenance strategies , 1. Top off with water & PH untill you reach a 100 percent water addback (topped off with 100 percent of your res volume) then dump and start fresh res as full strength. Works well with tap water to keep PH in check. 2. Plants do not excrete toxins from their roots so it is safe to say with 0ppm distilled /RO water , you can raise your ppm's back up to full strength During your top off and your res will last the entire grow. There is no need to flush or dump unless a nute build up has occurred. I feel plants may take more of this and a little less of that when it comes to nutrient profiles , so over time a res will get out of wack. I Like to combine the two methods , Dump every once in while , or when things start to act up. grab a second bin to place your lid on while dumping if breaking roots are your worries. Not so sure about the net pots , I run ebb & flow. I've seen small a big pots , the water underneath is where the magic will happen , so get those bubbles up touching the net pot.
I would rethink, using a big rubbermaid tote... and use an individual 3-5gal bucket for each plant. I used one rubbermaid tote for my first grow and they are weak, the water pressure from just filling it 70-75% full made the sides buldge out. I came across a tote at home depot that is made out of tougher plastic that i now use for my res. Plus all the roots get tangled, and your plants generally have less room to grow and breathe....I didn't like it at all, and my plants were deffinately over crowded. NO matter what you grow in for hydro, you should have a drain plug at the bottom. I've grown in GH waterfarms before, and they have a water level indicator tube which easily swivel. I would just swivel them down to drain out the water. as far as maintaing the proper ph/ppm levels....this is where the maintenance comes into play when doing hydro. I checked the PH, PPM, water level DAILY and adjusted as needed. There is no Golden rule, because different strains will use water/nutes differently. Also the climate, temp/humidity/light/etc, will all effect how the plant uses water/nutes. My dream grow room will have a doser...and eventually I'll get one. if you don't know, a doser adjusts PH/PPM/water level automatically. Very nice thing to have, but will set you back about $2500 as far as topping off vs. dumping and starting fresh. I would top off all through veg, dump and start fresh when starting flowering, then mostly just top off...but I dump and start fresh one more time @ about the halfway point of flowering.