Size/Depth of DWC tub important?

[SmokeDoggy]

I've got a super stealth grow box and I want to maximize greenspace and minimize hydrospace. So I'm thinking about using this:

http://www.lionsdeal.com/wi-pl-7k.html

It is only 7" deep, but I only plan to have 4 plants.

If you read Roseman's guidance, it is 6 plants and 6 gallons.

So for 4 plants, I'll need 4 gallons, right?

This will hold 9 gallons, so 1/2 full is about 4.5 gallons. So I'm thinking if it is 7" deep, and the net pots are hung from the top and then they hang down 2.5-3" (3.25" GH net pots), then that means I'll have 3.5-4" of water+aerospace depth. 3" deep at 20.25*15.5 dimensions makes exactly 4 gallons. So > 3" would be > 4 gallons in this particular setup. So it should be EASY to get nearly exactly 4 gallons with room for air, but that then only 3" of water depth.

How does this sound? Am I putting too much math into this?

I guess the real underlying Q is: Will the roots have problems if they touch the bottom of the tub (even if it is full of aerating/nute-enriched water??

 

[mista32]

im not an expert but it looks good to me i have the six gallon res. and the nutes are killinme gone thur a lot it will save a llot of nutes

 

[SmokeDoggy]

Yeah, I fear I will go through nutes too. Like I expect I might have to change the water weekly, depending on pH. If that is the case, I worry about wasting nutes. Then again, I read on another thread that someone was recycling their nute-water (which had bad pH after a week of use) and re-pH-balanced it, and used it the week after. Is this insane or would it work? Do the nutes go bad once in water (I would think so after 1.5-2 weeks at least)???

I read elsewhere this might be classified as SWC not DWC... LMAO!!!!

 

[mista32]

just got to worry about the root ball it gets pretty big

 

[LonghornFan]

You can grow 4 plants in there, sure no problem. Tons of air, light, and enough water to keep the roots in the water and give them air. Remember, when those plants get bigger, you have to pull that lid off every week or so for a water change. Could get pretty damn heavy, the lid that is, when they have 4 big plants and only one person doing the reservoir change..just my opinion. Can you go to buckets once the plants get going? Smoke, like you, I got to the point that I don't worry about cost to an extent...The most important thing to me is a good healthy plant!!

 

[SmokeDoggy]

I think for a single shallow tub like this I can use a 5 gal bucket and a hose pump for my weekly draining. That way I won't have to lift the lid, suspend it temporarily, worry about roots dripping all over the f'in place, etc... I just hope a siphon would work. There might be a lot of salt and other crud getting stuck to the sides/bottom of the tub (requiring a rub-down and multiple rinses). Maybe I'm overthinking it, but I don't have much else as far as choice. I could build a bigger box but I really like the one I have now..

 

[Illegal Smile]

That will work. I grew two plants in an aerogarden and its res is less than one gallon. So you would do this without a pump and feeder tubes? How would you water/feed them at the beginning?

 

[SmokeDoggy]

That will work. I grew two plants in an aerogarden and its res is less than one gallon. So you would do this without a pump and feeder tubes? How would you water/feed them at the beginning?

Naw, I'm going to get both the air bubbler pump and the water pump for initial feeding. Might as well, right?

 

[Illegal Smile]

Naw, I'm going to get both the air bubbler pump and the water pump for initial feeding. Might as well, right?

Like I said, I think you'll want to try it both ways. Get a robust air pump. The little ones will power 2 airstones at best but I'm using 4. More bubbles - fewer troubles.

 

[SmokeDoggy]

I'm planning on a 180gph water pump for 4 plants with 1/2" non-clear tubing. Should be plenty of flow.

As for the air pump, I'm looking at a 10gallon aquarium pump with 2 of the 12" long bar airstones (blue). I hope the pump is sufficient, if not I'll take it back and upgrade. I've seen some pics of good bubbling and it looks like there should be a thin blanket of pure bubbles/foam across the surface of the res or at least directly under each net cup.

 

[nug]

Hello SmokeDoggy, Im setting up a similar dwc. My plan is to use identical 22 gal rubbermaid tubs tho so when I swap the water I can snap the lid back on the the other tub without too much stress on the roots.

 

[Illegal Smile]

I think you want all the bubbles you can get. I'm using four 12 inch airstones.

 

[SmokeDoggy]

Illegal Smile - How big is your res and how many plants?

I might pick up some more and a bigger air pump - I don't want to skimp that's for sure!

 

[LonghornFan]

User air bubbles and feeder tubes if you are going to use the tubs and put the hydroton and rockwool with them. That way you can irrigate everything individually and keep the rockwool moist without making bubbles hit the bottom of the rockwool or hand watering or any of that stuff.

 

[Illegal Smile]

Illegal Smile - How big is your res and how many plants?

I might pick up some more and a bigger air pump - I don't want to skimp that's for sure!

8 gal tote with 6 gal of water and 4 plants. Here is the uber air pump

http://www.discount-hydro.com/productdisp.php?pid=412&navid=8

Texas, Yeah we know, some of us just don't like machines in our water and feeder tubes and question whether it is really necessary. Arguably it's not since the DWC people do equally well without it. Automation isn't always better than hands on.

 

[SmokeDoggy]

8 gal tote with 6 gal of water and 4 plants. Here is the uber air pump

http://www.discount-hydro.com/productdisp.php?pid=412&navid=8

Thanks Illegal Smile! That is one gnarly pump!!

 

[110100100]

I wouldn't bother with the water pump unless you really can't drain the tub. I've got a how-to from overgrow where the guy says he had np with growing plants out in the small tubs people use for aero-cloning. He said he was going to switch his bonzai mothers back over to SWC in a 6 inch deep tub. He said all he needs to do is give the roots a haircut every 6-8 weeks. Just make sure to give the room for the roots to breath and keep the bubbles hitting the exposed roots to keep them moist. He changes once a week.

Another tip would be to get a spare tub so when you go to change you just put the lid on the spare while you deal with dumping the tub or adjusting the ph. Put a little water in that tub if you have to stabilize it when the plants get bigger. No pain in the ass to deal with. Keeping an inch or two of the roots exposed inside the tub will lower the weight of the tub to about 40Lbs so it shouldn't be to tough to deal with.

Let me know if you want to see the how-to I saved a bunch of articles and threads from OG.

A tub, good air pump, stone and good nutes.

 

[SIV3L]

I have a 10 Gallon tub 2 airstones 6 plant setup and it works fantastic! Roots get huge but there is enough space for all of them. I wait 2 weeks before I decide to change water. If the levels are ok I wait 3 weeks. I would not recommend EVERY week nutes are not cheap and the plants should be able to handle it assuming you make sure the ph stays where it should.

 

[Kingb420]

i suggest a larger air pump than a 10 gal one..

i just set up mine, a 37L tub (almost 10 gal) with a 30 gal air pump with 2 12" airstones, i just get the bubbles to break ok @ 2 inches or so above, but i expected more from what i had. i should of got a 50gal pump, but it will work

 

[Illegal Smile]

If you are using the bubbles to feed seedlings, the bottom line is how wet your cube gets with the bubble action you have. You can increaseit by raising water level some, but you want new roots to grow down through that couple inches of misty airspace. A pump with more ability than you need is a good idea. So is a backup.