Pumps for indoor irrigation

I’ve been doing research for a while now looking for the best pump to be fitted to a micro irrigation system for coco flower rooms. The system itself it’s all set in place, but it is power by a danner 18 submersible pump which just isn’t giving us the psi needed to run the system effectively(putting out around 7psi, we are looking for 20-30). After all the danner pumps are pond pumps and arnt really designed to pressurize lines (even to the relitivl8low psi required for micro irrigation). The result is a system that isnt watering evenly and cannot be dialed in to water a precise amount. have also hooked up a sump pump that got us up to around 20psi, but the sheer amount of volume going through the lines seems to make the drippers put out alot more than their 1gph that is desired. Any idea of some affordable low volume, high PSI pumps out there?

By the way, we are pumping from 55gal reservoirs.
We are outputting 144gph total from the emitters.
There is no pressure regulating emitters or manifolds in the system either (maybe they would magicaly solve this problem? Just not sure if I need a proper pump to make them viable)

I have a sketch of the design if that helps, just not sure if it’ll show up

Hunter Scan 11.11-1.pdf (324.7 KB)


Can you give us a little more info on how many plants total. I use little giant 5msp pumps one pump for two tables and 36 plants total using a 70 gallon reservoir. It works well for me because I’m on a recirculating system with 3 gallon pots or soilless medium.


We run around 75-80 plants in this space. Generally 2 plants per 6 outlet manifold with 2 emitters per plant, leaving 2 unused outlets on each manifold. We arnt on a recirculating system yet (I’m hoping to get there…) and same story with the tables. I’m curious too if you have ever checked out psi and/or preformed an audit? My goal is something that we can really dial in and know exactly what we are watering.

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I tried what sounds like a similar system to yours when I started, when I switched from hand watering. I think I was over thinking the whole project, thinking I needed to have exactly the same amount of water to every plant. I never got that system right because I couldn’t get exactly the same water to each plant. I took a look at my buddies system and he showed me to not worry about exact amount to each plant just let the excess run out the bottom of the airpot through some paint filters back into the reservoir. I usually start with once daily watering in the beginning to up to 4 times a day towards the end. I’m definitely not telling you to abandon your plan just giving my thoughts of why I went through with a similar system.


Hey hey!

I would recommend a solid ~200ish GPH mag-drive pump for 144 GPH target. I would also recommend an inline pressure regulator or valve and some sort of pressure compensating emitters (they WILL solve a lot of this problem.)

A lot of growers are using a device called an Octa Bubbler. the they are 8-outlet pressure compensated manifolds that connect to 3/16" ID (standard 1/4" irrigation tube) and have either 2, 6 or 10 GPH flow restrictiors (which you can swap out for like $0.50 per bubbler.)

You plumb these in to standard 1/2 PVC and use a threaded raiser. You can use any sort of drip stake you want on the end, or drip ring. Put your pump on a timer and you are good to go!

You can also run standard irrigation tubing with pressure compensated button drippers if you want to go lower pressure

There might be some high tech pumps out there, but at 144 GPH, you don’t need much! Keep it simple.

You can take a low horsepower Leader or Grundfas and throttle it down with pressure regulators and a flow valve if oyu want to get REALLY serious. http://us.grundfos.com/products/find-product/SCALA2.html

Please let me know if you have any more questions!


So does that octabubbler have a certain operating pressure that needs to be achieved to make it work properly? It just seems too good to be true! We are running some danner 18 pumps now which I belive (not totally sure) out perform that pump you mentioned and we are only getting around 7 psi in our lines now with that. If having some pressure regulating manifolds is all we need to get more even watering I’m in! It just seems like that so simple…

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Hey! From what I have seen and experienced, the OctaBubblers are designed to run between 20 and 40 PSI with optimal pressure about 30PSI. They are awesome little devices and should solve your problems! I think they can be used at lower PSI, but that is what I usually shoot for.


Octa-bubblers are definitely taking over as one of the most popular ways to do drip irrigation on a large scale. Here’s a good pic of what they look like in use:


Good advice @casey. @milessadowsky has some pictures of his grow facility and he’s using octabubblers too. It looks like he uses a grunfos pump and I highly recommend them. They have a built in pressure regulating tank in the pump that can be adjusted up/down and pretty much maintenance free. Awesome pumps and not very expensive.


You’ll need about 1/2 HP (or more depending on manufacturer), in order for a submersible pump to get 40 PSI of pressure - and a minimum flow rate of about 7 GPM in order to keep it from overheating. A more efficient solution would be an external centrifugal pump, such as a whole house repressurization pump.

An even better solution would be a positive displacement type, such as a diaphragm pump.

Another thing about submersible pumps…some of them have two different metals in the impeller and pump shaft which creates a galvanic reaction. When placed in your nutrient tank, it will feed a corrosive process off the ions in your nutes! Disassemble and inspect…

In order to even out the water delivery to different sites, you’ll either need to redesign your fluid circuit or pressurize the system with an appropriate pump (diaphragm pump for most efficiency) and add pressure-driven emitters.


My reply may be a bit out of date, sorry. I just joined the group a few days ago. There are these cool pump units produced by DAB Water Technology (and yes that is their real name). DAB is from Europe and they produce pumps for industrial applications. They are reliable. Its a variable speed controlled pump unit that can maintain a pre-set pressure. I tend to use more horticultural grade drip emitters like Netafim or Rivulis pressure compensated drippers. These have set outputs (0.5 gal, 1 gal, etc per hour) and can operate on an incoming pressure range from 5psi-45psi. Anywho, here are the cool pump units for smaller applications.


Thanks for sharing that @dsolomon. We have a wealth of older topics from the beta so feel free to add to any older topics to reopen the discussion. It will bump that topic to the top of the list so that people can see your reply even if it’s on a past topic that is further down the list.


@TxGrow, would love to get an update on this one. I just noticed your feed system diagram and would like to hear about your experience after a couple months of running this design. Is there variation in plant yield/health? Also, curious about which pump and what zone size you settled on.


Here are our pump units…these are supplied by Hortimax. They are also the stock fertilizer solution mixing unit. Constantly injects, measures, monitors the fertilizer level by Ec and pH. We use a stock A/B + acid mix. This is the unit from our New York facility during construction. The large tanks in the back are for freshwater and recirculated drain and the smaller 30 gallon black tanks are the stock tanks.


Here you can see the injectors and small mixing tank


Hey guys, just thought I’d throw my 2 cents in (I work for Netafim and deal with designing high end large commercial irrigation systems for both traditional Ag/greenhouse crops and cannabis).

The Octa-bubbler method is on its way out, it was a method that was born of necessity and of not having access to commercial irrigation equipment and designers, and is not used ANYWHERE else other than cannabis in commercial Ag or greenhouse facilities. It was a landscape irrigation product designed to give some water to some plants sometimes, it was never meant to be a precision hydroponics device. Uniformity just isn’t there, the plants at the front get different amounts of water than the back, and even compared to a neighboring plant on the next octa-bubbler over. Uniformity in water applied is VERY important in all cases. If a larger amount of water runs out of the bottom of one plant compared to another, that plant will consequently have a lower substrate EC and higher water content, which steers the plant towards vegetative growth, and will negatively affect flower production compared to the plant that had less runoff (unless the runoff is good at the larger amount, which means the plant with less runoff will likely hit buildup toxicity).

We just switched over the Jungle Boys, who were one of the first to make the octa-bubbler method popular, and I’ve done a LOT of switching out octa-bubbler setups for low volume drip systems over the past year or so, with phenomenal results in every case. In general, its good to remember: if a product doesn’t exist outside of cannabis and it’s meant for managing root zone environment (irrigation, fertilizer additives, substrates, containers, etc) be very wary of it and make sure you have a thourough vetting process to evaluate it. There are a lot of people/companies out there that will relabel and sell a product never meant for crop production into cannabis just because they can, and they make a lot of money doing so. Doing an Octa-bubbler setup with floraflex caps will cost you upwards of $10 per plant site, where a commercial quality drip system will cost you less than 50 cents per plant site and will give better results (Netafim sells at the same price to everyone, whether you grow cannabis or cucumbers).

The rule of thumb to remember with hydroponic substrates (coco, rockwool, sphagnum peat, etc) is to keep the flow rate per drip site below 1.5 L/H (0.4 GPH). Anything higher, and you are guaranteed to see channeling and uneven wetting of the substrate. Octa-bubblers can only go down to 8 L/H (2 GPH) per spigot, which is 6X too high, and their pressure regulating feature is not very accurate to begin with.

Another good rule of thumb for anything other than rockwool is to have a low flow drip site 8 inches in all directions of the container (rounding down) for maximum distribution uniformity. For example, a typical 1 gal pot would have one drip stake, 3 gal would have 2, 5-7 gal 4 stakes, etc. Rockwool is simple: 4" cubes and under, 1 stake, 6" and big mama cubes 2 stakes, and 1 stake per plant in slabs, with a minimum of 3 stakes per slab (one in the middle if only 2 plants per slab).

Netafim and other dripper manufacturers make low flow rate drippers (although, even if I didn’t work for them, I’d still use Netafim just for the fact that they are the most precise and most clog resistant drippers available, and cost difference is negligible for anyone with less than 100,000 plants). Netafim has a 1.2 L/H drip stake assembly (PC dripper with check feature, length of 1/8" micro tubing, and stake) that works perfectly and can be used in any hydroponic substrate until you get to hydroton (expanded clay pebbles over 1/2" in diameter), at which point you’d use a PC spray stake instead.

As far as a pump goes, a simple $100 shurflo diaphragm pump with built-in pressure switch (they call them “demand style”) with a $60 pressure tank before your manifold of zone valves works great. Then you will always have the necessary pressure (between 12 and 50 psi for Netafim drippers, anywhere in between there they will put out exactly 1.2 L/H) and the pump will kick on automatically when it needs to repressurize. All you need is a simple cyclic timer like the $80 galcon that will let you set up a watering window during the day and turn on for X amount of time and off for Y amount of time for best results. Normal irrigation timers with only 3 or 4 start times per day won’t cut it for precision pulse irrigation (method with the best end results seen so far in all commercial crop production industries).

Hope that helps! Feel free to ask if anyone has any questions about the above.

Thanks for reading!



What is the Minimum required spacing between the drippers on the line they are installed in? Thanks for the post. I currently use your drippers at a facility in Reno NV. @JoshNetafim

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Hi @lassencannabisco

I wouldn’t put any more than one dripper per inch of tubing, but other than that you can put as many as you’d like on a line.

The maximum number of drippers per run of tubing is determined by flow rate and size of the tubing, keeping the water velocity below 5 fps (slightly above is ok, but not much and never over 7 fps, or you may have water hammer issues).

If you have a typical 1/2" poly tubing, aka 16mm or 17mm, the max recommended flow rate is 5 GPM per lateral. That equates to about 946 of the 1.2 L/H (0.32 GPH) drippers, or 473 plants in 6" rockwool cubes with 2 drippers per cube. If you have a different flow rate dripper, just add up all the drippers and multiply by flow rate and make sure it stays under 5 GPM (300 GPH) per lateral.

Hope that helps!


Thank you very much for your detailed reply. @JoshNetafim