Calling all 4x8 Tray guys!!!!

G

Guest

• Jul 19, 2007

• #1

I'm looking at a few things that will help me a design a system for someone. I'm looking at a couple different routes but they are mainly going to be either rockwool cubes on slabs or dynarok in pots both being top fed.

I'm trying to figure out roughly what water usage I will get from this setup doing drip irrigation recirculation. I will have 2 - 1kw lights over each. I'm basically in a situation where water is very inaccessible in the quantity I need it. So I'm trying to find the amounts of water I will be using and then plan from there how to get it.

I'd also like to know any tips you guys have for running trays. Its what i started out doing years ago and now I'm really intrigued by using it again in this case to keep it on the floor and running all plumbing underneath the floor. Giving me LOTS OF HEADROOM!

Also I'm working with a 7' headheight. I'm not thrilled about this but its what I have to work with.

 

D

dubracer

Member

• Jul 19, 2007

• #2

For a flood and drain setup and a 4x8 tray, you really need atleast a 70 gallon reservoir and 100 is a lot better. This will need to be topped off every week, probably with about 10-20 gallons. With a top drip system I would think less water would be used, but now you know what the most should be.

 

pumpkin2006

Member

• Jul 19, 2007

• #3

dubracer said:

For a flood and drain setup and a 4x8 tray, you really need atleast a 70 gallon reservoir and 100 is a lot better. This will need to be topped off every week, probably with about 10-20 gallons. With a top drip system I would think less water would be used, but now you know what the most should be.

Click to expand...

Very incorrect, you must have never run a 4x8 table with ebb n'' flow before, cause your talking out your.... anyways I have 2, I flood both of them at the same time with a 100 gallon res and it isn't even empty when they're both flooded. Also, about the 10-20 gallons... depends, I use coco, so that holds a lot more water, so maybe more, maybe less depending on what medium you're using.

Rockwool holds a lot of water, one of the reasons why I don't like it, so your water consumption shouldn't be horrible. Just make sure you doing recirculating and time how long it takes for the slabs to dry out; simple as that. We can give you a definitive answer, because we don't know enough information. Mind you, as you plants grow larger, they consumption will be paralleled to it; be prepared to bring in more and more water as time goes on. You may want to check out the coco slabs; many growers are using them in the coco section of this forums, parent forum. Also, PM Neptune, he does exactly what your talking about.

 

Last edited: Jul 19, 2007

G

Guest

• Jul 19, 2007

• #4

I am also considering watering multiple tables with a few resevoirs. This is really where I'm aiming, is having a ball park of usage, and going from there. I'm afraid of the shear weight on the floor. I figure if i ran what I'm planning of running I'm looking at atleast 16 lights in a space of 40x11 and if it too heavy it may just cave in the floor. I guess I need to figure out the weight 2x6's can hold and go from there. Making sure my floor can handle it. So what I was thinking is this, either 1 resevoir piped in or for ease 2 4x8's on a single resevoir.

I'm not trying to flood and drain, just top feed with a 1/4" line or two per bucket/plant.

 

fuzygrowth

Active member

• Jul 19, 2007

• #5

16 lights, 2 per table, 8 tables, 1 rez for 2 tables, 4 rezs, 400 gallons, 400x8 = 3,200 pounds plus your fat ass and all the equipment, plants, medium and what not. no clue if thats 'too much' weight, but it's alot of weight. g'luck man, keep us posted with some good pics.


ps. jk bout the fat ass

 

G

Guest

• Jul 20, 2007

• #6

Yeah, so that's not too bad across that sq. ft'age. So you think 100 gallons will fly across 2 tables, eh? I'm a little concerned. I'm thinking the res' will need to be topped off. Which again goes against what I'm trying to do which is set this up so a handicap person being of body or mind, lol... can run it and have plenty of water for a whole 7 day period and not overload the floor. Hmmmm, I guess I can just try it and see.

 

fuzygrowth

Active member

• Jul 20, 2007

• #7

you don't have water... like a hose? a pipe to tap into ? nothing?? you gonna bring it in by truck?

 

pumpkin2006

Member

• Jul 20, 2007

• #8

fuzygrowth said:

you don't have water... like a hose? a pipe to tap into ? nothing?? you gonna bring it in by truck?

Click to expand...

I second that question. What is limiting your water supply? Hope were not delving into a possible security breach; you can just say, I'd rather not talk about it.

 

G

Guest

• Jul 22, 2007

• #9

Lol... no security breach, its on a well. The guy doesn't have regular city municiples. Only so much can be pumped out, no idea what the max is. Hold tanks though should cover it, so that's going to be how it gets handled I guess.

 

G

Guest

• Jul 22, 2007

• #10

The more I think about it the less I think its a problem. However, if I didn't double the resevoirs up then it would become more of a concern. Mostly the weight though. If I had 2400 gallons of water on the floor over a 40x12 sq.ft area that would concern me heavily. I am really wanting to plumb it all to one tank outside, but I have to discuss it with him further.

 

somoz

Active member

Veteran

• Jul 22, 2007

• #11

hmm....a couple of things here bro.

first, i hope you already have a couple of rainbarrels, drums, etc stockpiled with water and are continuing to stockpile them. it would suck to be in midflower and find out you have to go buy 100 gallons of water from the store, a real pita that would be, especially if yer handicapped....

if you haven't already started this i would highly recommend it, this way you can start maxing out the water right now and keep a constant backup in case you fuck your plumbing up, worst case scenario and you need to refill the entire system. anyway, without water or some form of it you can't grow shit.....so, that's all that really needs to be said about that

if you feel unsure about the weight per sq ft of the room, resupport the joists from the basement and i know there is a site out there that does a calculation for a safe weight to sq ft ratio out there.....i've had to use a couple times before my self....ha

i use 150 gallon ressiez for a 4x4 and a 4x8, running plants at 1 per sq ft....works fine for me and you could easily get away with running two 4x8's off it.....i don't flood at the same time though, just my personal preference.

also, plumbing your rez to outside may have some advantages depending on your location but at the same time i wouldn't feel comfortable having my rez all exposed outside, not to mention bugs, kids, neighbors, etc......and there are the elements to deal with as well bro......

anywayz, sounds like you you're gonna have a lot to figure out with this project.....good luck with it man

moz

 

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willbeHigh

Member

• Jul 22, 2007

• #12

Iam a carpenter by trade.i have never build or seen 2x6 floor joists.Alway 2x10 ,2x12 or engineer joists.So where is this floor,the attic,thats what it sounds like to me.Floor joists are sit 16" on center.Cealing joists are 2' on center.So if it is a attic you will have to double the joists.You said the room is 40' long,thats 20 more 2x6x12'.But by some chance it is a ground floor your in luck.You can run one joist down the middle of them and brace it with 2x4s doubled, for up rights about 8' apart.If its dirt under the floor besure to use a {mud sil} mud sils are 16"x16"x1"1/2. 3/4" plywood doubled up.Adding joists will put the lbs per sq foot at about 1500 lbs.per sq foot.Under the floor the brace down the middle will bring the lbs per sq foot up to around 3000 lbs per sq.foot. One 2x4x8' end ways will support 800 lbs. so there you go.If can help anymore hit me up.PEACE

 

G

Guest

• Jul 23, 2007

• #13

pumpkin2006 said:

Very incorrect, .... anyways I have 2, I flood both of them at the same time with a 100 gallon res and it isn't even empty when they're both flooded.

Click to expand...

what do you call a flood.... 2" of water?..lol.

Dubracer is absolutely correct.... to flood a botanicare (true 4x8) tray properly a 150 gal rez works well for low maint. it's not possible to flood 2 of em at the same time with a 100 gal rez period.

top feed takes much less water.. you can top feed 2 4x8's with a single 100 gal rez easy.

 

Last edited: Jul 23, 2007

T

terran2

• Jul 27, 2007

• #14

forty grit said:

what do you call a flood.... 2" of water?..lol.

Dubracer is absolutely correct.... to flood a botanicare (true 4x8) tray properly a 150 gal rez works well for low maint. it's not possible to flood 2 of em at the same time with a 100 gal rez period.

top feed takes much less water.. you can top feed 2 4x8's with a single 100 gal rez easy.

Click to expand...

That was what i thought lol.....a 4 x 8' table holds approx 100gals given that a 100gal rez is 4x4' x 12" tall <g


Problem with E&F on a 4x8 table is the added length of time for the drain which takes the total to just over 20mins with a 750gph pump sometimes which is a long time for roots to be sitting in water , but oh well . 1200gph on a full one inch throat would fill the table faster and drain faster too . I think this is how i would approach e&f on a 4x8' table .

Thinking of going to top drip myself , here pico demos his hard pvc manifold set up
http://www.icmag.com/ic/showthread.php?t=62654

 

gottt it

Active member

• Jul 30, 2007

• #15

i use a 100 gallon res and it seems to take me about 300 gallons for a whole cycle .

 

pumpkin2006

Member

• Jul 30, 2007

• #16

terran2 said:

That was what i thought lol.....a 4 x 8' table holds approx 100gals given that a 100gal rez is 4x4' x 12" tall <g


Problem with E&F on a 4x8 table is the added length of time for the drain which takes the total to just over 20mins with a 750gph pump sometimes which is a long time for roots to be sitting in water , but oh well . 1200gph on a full one inch throat would fill the table faster and drain faster too . I think this is how i would approach e&f on a 4x8' table .

Thinking of going to top drip myself , here pico demos his hard pvc manifold set up
http://www.icmag.com/ic/showthread.php?t=62654

Click to expand...

First off, I'm so confused as to how a 750gph pump takes 20 mins to fill one table.... secondly, your right, I don't have bontaincares "true" tables, but my black tables are 4'x8' on the outsides, and I flood both of them about 4", which is quite sufficient if your using flood net pots. I don't see why you would need to make things more complicated and have to pump extra amounts of water, when its not necessary.

Heres how it goes 10" square net pots that are 5" tall, on 1/4" tick coco root mat with hydroton filled in-between all of the pots, up to the top of all of the pots. The mix inside of the net pots is 60% sunshine bagged coco and 40% fox farm big n' chunky perlite. This mix displaces a lot of water. I flood 2x a day and never have over or under watering issues. So... maybe this shows you guys, the reason it works for me. I bet most of you use hydroton only and therefor it requires a lot more water.

 

M

Manchineel

New member

• Jul 21, 2017

• #17

I was contemplating starting a new thread on this topic, but figured I'd just rehash an old one.

I intend to set up a 4x8 table in a 5x9 tent. I want 8 plants, which will all be in coco and fed on a timer. Ideally 6 x per lights on.

Now, I've read that a 4x8 has caused some problems as far as DTW goes. More than one individual has stated so.

Can anyone further clarify the issues one might encounter using a 4x8, which I guess in the grand scheme of things is rather large, when it comes to multiple feedings of coco, DTW?

Humidity is my friend, if that's the concern.