Coco irrigation.

hello all,

I am in process of building a 8 x 8 flower room with 4 lights.

I’ll be using coco and want to set up automatic watering irrigation system.

I’ll be using 1 x 100 gallon reservoir and planning to have two 4x8 grow trays.

Here are the questions.

1. I’m thinking about using one submersible pump (1/4 hp, 1200 gph) to feed two 4x8 trays. 6 plants in each tray. Is the 1200 gph enough for my needs?

2. Recomendation In pump please.

3. Thinking about hooking up 1” pvc to the pump (mainline) and tapping two 1/2” pvc to each grow tray. What do you think,

If you have any others ideas on plumbing, please let’s me know

Thanks in advance

You grower friend

My opinion is smaller feeds (say 50 or 60 ml) every few hours depending on climate, is better than large waterings less often.
Use at least a dripper on two sides or one of those fancy green plate things that go on top and guide the water down many holes.

Thanks ANC

Yes I forgot to mention. 1 x 1” main pvc line to 2 x 1/2” pvc line to 24 - 36 1/4” flexible tubing. 2 to 3 1/4” lines to pot.

How about the pump size. You think it will be enough? Or too powerful that it might get mixed in with air??

I run coco drip dtw using x4 DE's in a 9 x 12ft room. I can say this:

1. your pump is sufficient but you'll need to test flow rate to know how much its providing in a given period, then calculate your fertigation rate based on this;
2. how far is your plumbing having to run and what is the max head of the pump?
3. watch out for syphoning - the struggle is real!
4. I recommend running a recirc pump in the tank cos 100gal is large (could you consider 2 separate res instead? Allows you to meet different feeding needs of strain varieties etc)
5. PVC is cheap and strong but how are you switching over to flex tube/vinyl hose?
6. be sure to build out as a loop manifold to each table to equalize pressure; you will lose water pressure over a straight line and the plants at the end will be watered less
7. think about steaking drip halos or Blumats or sprinklers for delivery. I build my own halos from 1/4 hose and they work good provided you keep 'em clean (they will salt up over time).

ANC said:

My opinion is smaller feeds (say 50 or 60 ml) every few hours depending on climate, is better than large waterings less often.
Use at least a dripper on two sides or one of those fancy green plate things that go on top and guide the water down many holes.

Click to expand...

You're correct to say this is environment-dependent. I had been feeding 8x1min in peak bloom but in a hot and dry room this can lead to salt buildup and lockout issues. Larger waterings less often have allowed more runoff and therefore keep the root zone in better health.

Knowing your flow rate is essential to getting this right. And also bear in mind that with brief waterings more often you will need to adjust EC accordingly (lower salt concentration preferred with regular waterings).

Thanks ruwtz,

When you say equalizing pressure, can this be achieved by installing a 1/2” ball valve to the pipes and valves to each pot? Or I will install one pump for each table?

I wish I can have 2 x 50 gallon reservoir but my room is small so I don’t have the area to put it. But I will think of somthing. I already have the reservoir and do not have lots of cash to buy different reservoir.

Installing circulation pump. Should I install it outside so that no heat issue is present in the reservoir? My resevior size is 53” x 53” x 13” tall. Please share ideas on how to recirrulate the water in the resevior without heating up.

I will watch on siphoning by making sure the angle my 1/2” pvc pipe. The end that is further away from the pump will be higher!?!

Thanks a lot

Denny Min said:

Thanks ruwtz,

When you say equalizing pressure, can this be achieved by installing a 1/2” ball valve to the pipes and valves to each pot? Or I will install one pump for each table?

I wish I can have 2 x 50 gallon reservoir but my room is small so I don’t have the area to put it. But I will think of somthing. I already have the reservoir and do not have lots of cash to buy different reservoir.

Installing circulation pump. Should I install it outside so that no heat issue is present in the reservoir? My resevior size is 53” x 53” x 13” tall. Please share ideas on how to recirrulate the water in the resevior without heating up.

I will watch on siphoning by making sure the angle my 1/2” pvc pipe. The end that is further away from the pump will be higher!?!

Thanks a lot

Click to expand...

Equalize pressure by building a loop of pipe instead of a straight line. Feed your 1/4" tubing off this loop; water pressure will be equal at any point on it.

I'd be thinking about a separate pump per table but thats just me.

Circulation can be on a cycle timer, something like 1 min on for 10 mins off, then no risk of heat.

You can avoid siphoning by installing an anti-siphon valve at the highest point of your pump line.

You dont need a loop to equalize pressure. As long as you run like 1/2" main line and then run spagetti line off that all lines will have same pressure. For siphon just put a dripper in the poly coming out of the rez at the top of the rez. Also you dont need a pump to recirculate your nutes.

westcoast420 said:

You dont need a loop to equalize pressure. As long as you run like 1/2" main line and then run spagetti line off that all lines will have same pressure. For siphon just put a dripper in the poly coming out of the rez at the top of the rez. Also you dont need a pump to recirculate your nutes.

Click to expand...

You WILL lose pressure over the length of a line; first 1/4” hose will be great, last one not so much. I’ve done it very recently. Esp true on an oversized mainline also, surely?!

And no you don’t need the pump but in a res this big I would think it worth it.

Been running drip irrigation system in my rooms for over 7 years and never had a difference in pressure when running a larger main line then smaller line off that.

westcoast420 said:

Been running drip irrigation system in my rooms for over 7 years and never had a difference in pressure when running a larger main line then smaller line off that.

Click to expand...

Props to your big pumps! And, this has as much to do with water volume as pressure.