Nick, For years, I avoided using a proprotioner to deliver fertilizer products to my orchids/bromeliads. Back in the '70s, I worked directly with proportioners in a different industry. They infrequently malfunctioned. Infrequent doesn't cut the mustard when it comes to my orchid collection!

This year, I decided that I would try it. It works very well with very careful monitoring.

One HUGE advantage to using a proportioner is that through dilution ratios, it gives the user much greater control of the delivered product. I can deliver a precise amount of fertilizer through my 16:1 proportioner. Generally, I now fertilize on a DAILY basis, except when it rains!

Let's not forget that some other products (such as IMIDACLOPRID) can be delivered through proportioners. Some vendors refer to these products as "ready to spray (use)" from a hose. Same thing. It's a proportioner! :)

--Stitz--

I think when you say proportioner, you mean a device similar to the siphonex that we use around her. I use it for the general outdoor population who get watered with tap water and the 16/1 ratio works great.

The low volume pump, 3 gallons per minute, I use to deliver the RO water for the GH plants, does not give a flow rate high enough for the proportioners to work. That's where this new unit comes in.

Nick

For the purposes of this discussion, I define a proportioner as any device which meters one chemical with a different chemical to deliver a measured product.

--Stitz--

No argument there but I wanted to stimulate a discussion on devices that work when, for some reason or other, these proportioners cannot be used. Mine works great in the yard but does not work in the greenhouse.

Nick

Some of us with a large g/h don't use an automatic watering system or a proportioner to apply fertilizer so can't add anything to your discussion.

Does your r/o system only give you three gallons a day?

Brooke

The RO system makes 40 gallons/day which are stored in 2 x 40 gallon plastic garbage cans joined together. A sensor shuts the system off when water gets near the top of the cans and then turns it back on when water is used, the cans therefore are always full.

The problem is that they are not under the usual city water pressure. People have devised different ways to pressurize for watering purpose, I use a 'Demand Pump'. You normally find those in motor homes where they go on as you open a faucet and shut off when water is no longer needed. Mine is slightly larger than a clenched fist and delivers 3 gallons per minute at 49 psi which is perfect for watering. I used a coiled slinky hose with a multi head wand, I pick it up and start watering, at that moment the pump goes on. No need to turn anything on or open any valves. As I shut the water wand off, the pump turns off. The pump is always on but only works as water is needed, works quite well. It also is 10 years old and has worked flawlessly all that time. Guess one of these days it will have to be replaced because of age.

I would also like to hear how other people obtain pressure for their RO water, especially if they have larger systems. When the day comes, maybe there is a better way to do this. DI water, by the way, is under city pressure so none of this is necessary but DI water is much more expensive.

In any case the flow rate is to low to activate the venture valve in the proportionisers Stitz is talking about which is why I have dealt with the units I have talked about.

If you have a large GH and use RO water, how do you fertilize?

Nick

I use r/o water to supplement my rainwater when we go through a drought. I collect rainwater in two 500 gal. outside tanks which is then pumped inside.

Inside the water can go into either a 275 gal. tank or in a 175 gal. tank on opposite sides of the g/h. Each of those tanks have their own separate pumps on the outside of the tanks and there is mega pressure with the two pumps. The r/o water drains into the bigger of the inside tanks when I need it. My system only makes 30 gal. per day and doesn't come close to my typical daily needs.

Last year we were in a big drought so added two 300 gal. tanks under two of my tables that hold plants. Those tanks are covered in polycarb to keep the run off out of the water. To empty these tanks into the bigger tanks we use a sump pump type pump which any big box store has. I have used the sump pump to water plants when I get lazy. The other two pumps came from Farm Tek.

We use a toilet float valve thingee on our water cooler system since it replaces water constantly from drip loss on the wall.

Back to your original question, I fertilize by hand just like I water by hand (hose/nozzle). I can't figure out a way to do mass watering since I grow many different things in different media in different size containers plus all the mounts in many locations.

Brooke

That's quite a system, Brooke, I almost did something similar. 10 years ago I looked at a guy's RO system where he had a 100 gallon reservoir with a submersible sump pump in the bottom which to led to his watering hose, syohonex in between. The neat part was that he used a wireless remote controll device to turn the sump pump on and off allowing him to stop and go with his watering anywhere on his property. Radio shack, I believe, people use it to turn on the lights in their house from the car.

I almost did that but felt uncomfortable with a pump sitting indefinitely in the water, realy no problem but I did not like that idea then, would do it today.

Nick

On the different needs, I basically have 3 maim areas each with subgroups.

1) The cold greenhouse. RO water 2 or 3 times a day with weak fertilizer. All get treated the same way except that some sit in trays of water.

2) The warm greenhouse. RO water with higher strenght of fertilizer (This only requires the flip of a switch). One quarter is devoted to drier plants which don't get the daily deluge, everyone else gets watered at least once a day with some, mostly the Bulbos, sitting in trays of water.

3) The lath house (back yard under shade cloth). Tap water, syphonex adds fertilizer at 1/16 dilution. Everyone gets watered the same except a dry area where the big pots and the drier plants get watered only once or twice a week.

I think this is painless and if I wanted to be more specific I would go crazy.

Nick