Trying to control my watering amount more precisely

[phxazcraig]

TLDR LOL

Just use a dry pump that can pull water from the tank and that will also pressurize it, if you want precision watering you want constant pressure, it's achievable using for example a 30psi pump for one "small" zone or a 60psi (better solution imo), on the main lines and 30psi pressures reducer per zone/tent/irrigation loop.

Than you control water flow by using different rates pressure compensated button drippers before your actual plant dripper. you can use the rated drippers to achieve your desired flow of water per time. there's 1-2-4-8L and 16L per hour button drippers afaik, after that it's only some simple math to achieve what you want.

I'll ponder on that, but it's completely different from the current system (using halo drippers). Sounds basically like an in-ground irrigation system here.

Thanks, but I'm going to try a bit more on my design as it is very close to working (and I have seedlings in red solo cups now so need to finish this).

My latest alteration is simply to buy a much smaller pump (95gph) instead of the 800gph unit I was using to fill the upper bucket. With this new system I will fill the upper bucket with 1/8" ID aquarium tubing, so it won't overflow the bucket. Everything else works fine. And it's both easy and cheap, ultimately.

Here's the TLDR description:
... 30-gallon reservoir holds nutrients and is refilled by hand 2x weekly. Small pump in reservoir continuously pumps nutrient solution into a 5-gallon bucket perched above the reservoir. Bucket has two holes drilled near top with spigots installed to allow continuous drain back into the reservoir. Second pump in 5-gallon bucket hooked up to timer and set to feed Drain-To-Waste system as often as every 2 hours. Pump in bucket always seems the same head pressure so gives (MUCH) more consistent flow than feeding directly from the bottom of the reservoir.

 

[Trash_2002]

I'll ponder on that, but it's completely different from the current system (using halo drippers). Sounds basically like an in-ground irrigation system here.

Thanks, but I'm going to try a bit more on my design as it is very close to working (and I have seedlings in red solo cups now so need to finish this).

My latest alteration is simply to buy a much smaller pump (95gph) instead of the 800gph unit I was using to fill the upper bucket. With this new system I will fill the upper bucket with 1/8" ID aquarium tubing, so it won't overflow the bucket. Everything else works fine. And it's both easy and cheap, ultimately.

Here's the TLDR description:
... 30-gallon reservoir holds nutrients and is refilled by hand 2x weekly. Small pump in reservoir continuously pumps nutrient solution into a 5-gallon bucket perched above the reservoir. Bucket has two holes drilled near top with spigots installed to allow continuous drain back into the reservoir. Second pump in 5-gallon bucket hooked up to timer and set to feed Drain-To-Waste system as often as every 2 hours. Pump in bucket always seems the same head pressure so gives (MUCH) more consistent flow than feeding directly from the bottom of the reservoir.

Gotcha, if you want/need precise irrigation in the future there's a proper way.

 

[phxazcraig]

OK, it's actually working!
It's not pretty, but it is cheap. And it's convenient in some ways by having things at waist level. After a series of mistakes getting both a small pump and the right tubing, I finally have something that works.

It is a 50gph pump in the 30 gallon reveservoir feeding a bucket above. Twin drains running back into the reservoir ensure a consistent water level in the bucket. Previous attempts included an 800gph pump that overwhelmed the drain back system.

Now all I need to do is fill the big reservoir. With feed pump in the bottom of the reservoir, my watering amounts were very inconsistent. When water level was low, the amount pumped was about half compared to full.

Right now im doing a feed every 4 hours of about 3 gallons. I can dial that back and easily see how much was fed by looking at how much left the feed bucket.

There is a black line coming out of the white bucket going to the 4x4 tent. It is the feed line and connects to a 800gph pump in the bucket. It is connected to a timer on the far right. Sticking out of that line near the top is a hole which breaks a siphon at the end of a feed. I stuck a small irrigation valve and a couple of inches of tubing to help direct overflow back into the bucket during a feed.

At the bottom of the blue 40 gallon reservoir is a 50gph pump running continuously pumping water into the bucket thru the smaller clear tube. there are two spigot draining the bucket into clear tubing that go back into the reservoir. An air bubbler in the reservoir keeps it stirred up. An automatic pH controller feeds pH Down into the reservoir via a very small line.

It's worked ok the last 2 years without the bucket, but I was constantly fiddling with feeding because of inconsistencies.

 

[phxazcraig]

Update on my system after harvest. I had a number of issues with the bucket draining until I added two more drains. With the setup I show above, I would get air bubbles blocking the drains a bit to the point I overflowed the bucket. Finally I drilled two more holes, added grommets and two more hoses (same diameter show in pic), and no more drain overflow.

I did have a lot of algae try to build up, particularly in the feeder line from reservoir into bucket. And some in the drain lines. To address that, I added some %12 peroxide into the lines, with the pumps shut off. This would cause immediate bubbling, some steam and a lot of heat in the drain lines. If I tried to cap the top end of the feed line, pressure buildup would blow it off the reservoir pump. Very effective in controlling algae, and it helps to oxygenate the water too.

Before the canopy covered the tent from side to side, enough light hit the plastic drain lines out from the plant bases and caused green algae to form. I added a few drops of peroxide to the drains here and there to cure that issue. Once the leaves covered all, it was too dark under the canopy for algae in the drains to be a problem.

Benefits to this Rube Goldberg contraption? Completely repeatable and accurate feeding amounts. Really solved that problem completely, once I solved drainage issues and siphon break issue. I may re-engineer the 'drain bucket' again (one larger drain instead of 4 smaller ones?) but I will definitely go this route again for my next grow.

I did measure my yield, finally. Platinum Kush, 4x4 tent, 700w light, 4 plants: 26 ounces of bud. About as expected. Used GH 'normal' feeding schedule.