Recirculating water table for phrag culture

[Ray]

I tried it once in the past. Fist reply was rotting within few days. Remember a pic of delenatii in situ took by Mr. Cahn. Roots were always wet by dripping water but on the surface of rocks so they could breathe.

To me, that reinforces my thoughts on root growth: Yes, they need both air and water, but they can grow in a way that makes different conditions acceptable.

Move a plant into semi-hydroponics, for example. You MUST pot it with the roots above the static reservoir, or they will rot. However, over time, the plant will grow its roots down into the reservoir, so will be submerged at all times, but do not rot, and in fact, they plant will do better than ever.

In the case of the "ebb and flow" nature of the concept in this thread, I believe the best option would be to have the tray be deep, have the pump flood it completely on a timer, then let it drain.

That could be accomplished by having a standpipe to set the maximum depth, but have a smaller hole in its base (or the tray bottom) to allow the water to slowly drain. (I am assuming the pump can lift more water than the hole can drain per unit time.)

 

[xiphius]

Long overdue, but finally finished the install, with a few changes. Adding the elbows changed the drain rate enough to pretty drastically raise the water level, so I added a ball valve to help regulate the equilibrium water line. Right now I just have them sitting on overturned disposable bowls to raise them up a bit and they are sitting in about 1/2 - 3/4 inches of water (a bit less than the 1 inch or so they were in originally). However, since the water line won't be changing with evaporation, I don't have to worry about keeping them standing as deep (more air!). I may adjust the water line a bit, but the overall setup seems to be working splendidly.

In future, I am going to rebuild the tub and try to implement Ray's idea of using a standpipe from the bottom. This will make customizing the water depth even easier.

The valve:

Valve setup:

New water line:

All installed:

Cheers!

 

[NYEric]

Looking good. I just put small aquarium pumps (Fluval 1's) in trays with water to circulate the water.

 

[MaxC]

Curious about updates on people's experiences on recirculating water culture. Though not a recirculating system, what about using an aquarium pump and splitting the line (see attached) and oxygenating each individual plant thus eliminating the risks associated on a single large tray?

 

[Ray]

Not sure what you're suggesting, Max. The airstone is to keep the water oxygenated. The water is still a shared bath. Putting air into individual pots does not change that.

 

[MaxC]

Using a splitter on a single air pump you could split the one source of air into 12 lines and run each line into an individual saucer for each plant, no?

 

[cnycharles]

Max, you are correct, a splitter would divide air into each pot separately. But ray is saying that having one source for all pots and having all water return to the same common area is potentially problematic. You could have a splitter and divide the water source to each individual pot and let the drain water escape or be discarded. Many greenhouse/nursery irrigation systems utilize this watering method but then it isn’t hydroponic or semi hydroponic irrigation, it’s simply highly directed irrigation. You could do this but collect the drain water and reuse, Ive thought of this but didn’t have time or place to do
https://www.horticulturesource.com/fresh/product/grodan-dutch-leach-tray-kit-6-x-40/

I have a grodan leach tray, here’s a kit for one, 13$. They are made to hold a slab of growing media and the water goes in and out the bottom. I modified by drilling a hole near the top of the tray and putting a bulkhead drain. The second tube that is meant as a drain, it goes back into the bucket which sits under the one end. The top drain also returns via the same end and down into the bucket. The drain line hooks into one of the elbowed fittings. I rotate up the fitting/line to raise the water line but mostly I want the water almost to fill the tray completely and go out of the top drain. Then the pump turns off via a timer and the water flows back into the reservoir in the tube from the pump.

I have a strong pump which could easily overflow the tub it’s pumping into. Since I live in a second floor apartment and this is in the living room that has carpet, and I’ve already had a kitchen sink overflow and mess up the ceiling below, I don’t have option for the tub overflowing and have built ability to help prevent this. Someone with this in a different setting and a gentler pump might not need to install the top drain, just adjust return line to get the proper fill level.

I also have a tub with a bulkhead fitting in the bottom. The water inflow tube comes up through the fitting, blocking most of the return water so the level rises. Pump turns off and all the water drains back down through the tube/pump and around the gaps between tube and drain fitting. The leach tray has phrags and other wet things and waters every day. The other one has different timer, and waters once a week.

Last year I was away two weeks and this worked sufficiently so that everything was fine when I returned. Some things might get a little more or less than they are comfortable with normally in a weekly or daily regimen, but for a vacation I watered well right before leaving and they get watered close enough for the rest of the time.

These could be adjusted differently, but I was having trouble finding tube line to fit the bulkhead drains and elbows etc, and since pots tip sometimes and potting media would try and jam drain tubes and openings I opted to not have return tubes on the bulkhead drains. But anyone could come up options that prevent clogging.

man option for people to use trays and water for their orchids could be to change their media to be more open, and/or use net pots for increased air. I’m sure phrags grow in very humid environments, and very wet, so it’s the need to have better air around the roots or have circulation/air stone. I think net pot would work with chunky perlite

 

[MaxC]

Could you just put a check valve on each line and not to worry about back flow? Did not include that in my explanation.

 

[eds]

Could you just put a check valve on each line and not to worry about back flow? Did not include that in my explanation.

Check valves increase the pressure on your air pump, shortening diaphragm life and the amount of air produced. The rubber also perishes so after a few years when your pump packs in the valve doesn't always work! Much better to site your pump above the water line to prevent a back syphon.

 

[MaxC]

Check valves increase the pressure on your air pump, shortening diaphragm life and the amount of air produced. The rubber also perishes so after a few years when your pump packs in the valve doesn't always work! Much better to site your pump above the water line to prevent a back syphon.

Thank you Ed, good to know. I may try this at some point since it does not seem to be that difficult to rig up or cost very much. Which type of air stone would you potentially use (i.e. ceramic, glass/silica) ? I would be worried about potential salt accumulation.

I am leaning towards the volcano (below) but not enough space.

 

[eds]

It depends what you're trying to achieve. And please note my knowledge about air is in aquaria and ponds - not hydroponics. In aquaria and ponds air is used primarily to move water - it doesn't really oxygenate the water but, by moving the water, it brings new water to the air/water interface where gaseous exchange can occur.

Air inside a pipe can also be used very effectively to move water - I turned over a 5,000 gallon (real gallons not your little US ones!!! ) once an hour using just 35W air pump.

So cheaper airstones with larger bubbles give less back pressure and are cheap to replace as they start to block up over time.

If you are splitting the air into 12 you will need a pretty pokey air pump such as the large 35W types. If you're just trying to prevent stagnant water in a reservoir I'd use a smaller pump with a larger single airstone. If you do split the air supply you will need a valve on each line to regulate the flow otherwise it won't be balanced.

 

[MaxC]

Goal is to provide close to ideal water conditions for a Phrag vittatum and other Phrags that will sit in standing water. Since the vittatum needs pure water not much I can do to give it a chemical boost but I can potentially give it a little movement in the water with an aquarium bubbler.

(Our gallons are the perfect size, they are the same size as our plastic drinking glasses for coffee and soda pop.)

 

[Ray]

Nothing is going to grow very well with just water.

 

[MaxC]

There is some fertilizer but extremely infrequent and a top dressing of moss.

 

[NYEric]

Max, I reduced the number of Phrags I grow sitting in water, it kind of destroyed my floors and I had a problem with condensation leaking down into my neighbor's ceiling. You can do either, move the water (water pump) or add air (air pump and filter stone). Just anticipate any growth and have equipment for the end result.

 

[Gerryhain274]

Good info

 

[xiphius]

Somehow, I missed that this thread got revived. But it reminded me that I should probably give an update. Two years in and I am loving the recirculating water table! Pretty much everything in it is growing well. No issues with rotting so far (*knocks on wood*).



I never did get around to changing out the tub. I will eventually, but I just haven't found the time. I also need to change out my fluorescent tubes. I am seeing some plants starting to elongate a bit more than I would like, so I think the light output has probably dropped a bit too much (fewer flowers the past 6 months or so too). Growth has been great though. I actually don't really do a complete change of the water very often. Maybe only 1-2 times a year. Other than that, I just make sure to top it off as needed. I actually recently added a float valve and tied it directly in to my RO system to make that part easier and more automated. I was initially worried about salt buildup in the water, but that doesn't really seem to be much of an issue. Algal growth seems to take care of the excess mineral salts pretty handily. When I notice too much algae, I just scoop a bunch out and throw it in the garden. I do periodically rinse salts/algae off the exterior of the pots.

Max, I reduced the number of Phrags I grow sitting in water, it kind of destroyed my floors and I had a problem with condensation leaking down into my neighbor's ceiling. You can do either, move the water (water pump) or add air (air pump and filter stone). Just anticipate any growth and have equipment for the end result.

Ouch... bet that was a fun conversation to have with your downstairs neighbor . Yeah, it can be hard to have so much moisture inside. The basement I grow in now is all concrete, so it isn't as big of an issue. In my old apartment, my grow tent and misting system definitely created lots of mold issues that were difficult to keep under control. In the winter, I would get so much condensation on the inside of the windows in that room that it would actually create an ice dam inside the apartment on the windowsill on exceptionally cold days.

 

[Ray]

A highjack for a humorous story:

I had a friend who was big into aquaria and plants. He had a tank water changer that squirted fresh water into the tank while simultaneously siphoning off some, allowing a slow transition to clean water without shocking the fish. The siphoned water was great for watering plants at the same time.

He was doing just that, enjoying a bit of “herbal refreshment” at the time, and fell asleep while watering a particularly large potted plant. He apparently slept for hours, the pot and tray overfilled early on, soaking his carpet and running under the walls to the apartments on either side, plus draining into the one below.

His new apartment was, at least, nicer...

 

[xiphius]

He apparently slept for hours, the pot and tray overfilled early on, soaking his carpet and running under the walls to the apartments on either side, plus draining into the one below.

Yup... this is exactly why when I used to fill buckets directly from my RO system, I always set them in the tub. That way, if I forgot about them, at least it was just running down the drain. Then I finally bit the bullet and got a storage tank because I got tired of forgetting about buckets in the tub .

 

[rwalsh]

My R/O is set to go to a livestock water tank valve (from Fleet Farm) attached to a seven gallon plastic bucket, set on top of a laundry tub. R/O wastes a lot of water as a by product besides the damage it can cause overflowing.