Eb & Flow construction question?

[JamesFarmer]

Hello All,

I am working on a small E&F system to tinker with and have the design fairly well figured out except one detail.

I have bulkhead fittings for the supply & drain lines. The bulkhead fittings project into the masons tub (Home Depot) a bit over 1/8".
I am concerned that the drain fitting not being flush with the bottom of the tub will leave 1/8" of nute solution standing in the bottom of the tub after draining.

Is this a problem? Pythium & algea issues in the small amount of standing solution?

If it is a problem, I can come up with an alternative drain. I prefer not as I already have the bulkhead fittings.

What do you all think?

 

[Medium Pimpin']

You won't have a lower plumbing area like most flood trays with that setup.
You could pitch the tray slightly towards the drain side.
You could also cut to fit an egg crate lighting diffuser to put in the tray to avoid pots sitting in water.

You can also use panda film or reflectix over your pots to keep light out of the tray, don't give the algae a chance!!

 

[JamesFarmer]

You won't have a lower plumbing area like most flood trays with that setup.
You could pitch the tray slightly towards the drain side.
You could also cut to fit an egg crate lighting diffuser to put in the tray to avoid pots sitting in water.
View Image
You can also use panda film or reflectix over your pots to keep light out of the tray, don't give the algae a chance!!

Thanks for the suggestions.

My plan is to follow Snype's idea and place a solid lid on the tub and suspend netpots in the lid. They won't be sitting on the bottom. However, there will be roots hanging low enough that they will touch the bottom.

I have considered pitching the tub a bit. If I do there will still be some standing water.

I have come up with an alternative that will allow almost all of the solution to drain but it is more difficult to build. Is this necessary?

Thanks again.

 

[canna woop!]

Could you widen the hole so it's flush with the bottom of the tray and connect a pipe or glue a funnel to drain out

Edit. I may have missed your actual question..

 

[JamesFarmer]

Any thoughts on potential troubles using the fittings I have?

 

[testymctester]

In my experience, the standing water is an issue and needs to be dealt with (preferably removed). I usually have the flood table directly above the reservoir. One solution I have used with home built setups is to just drill a couple small holes in the floor of the flood table so that it completely drains after a flood.

You can drill them in the middle or the corners of the table, wherever the water collects. My water pump flows enough to flood the table to the desired height even with several small holes drilled in the bottom.

Medium Pimpin's suggestion of the egg crate to get them off the bottom of the table will work well too. I have also used that approach with flat bottom tables that prevent adequate drainage.

Good luck!

 

[JamesFarmer]

In my experience, the standing water is an issue and needs to be dealt with (preferably removed). I usually have the flood table directly above the reservoir. One solution I have used with home built setups is to just drill a couple small holes in the floor of the flood table so that it completely drains after a flood.

You can drill them in the middle or the corners of the table, wherever the water collects. My water pump flows enough to flood the table to the desired height even with several small holes drilled in the bottom.

Medium Pimpin's suggestion of the egg crate to get them off the bottom of the table will work well too. I have also used that approach with flat bottom tables that prevent adequate drainage.

Good luck!

I hadn't considered that the grids will hold the roots up off of the bottom as well. I may give that a try.

If my res was going to be directly below the table I would simply drill the appropriate holes as you described. Unfortunately that isn't going to play as my res is off to the side.

Thanks again for your input.

FJ

 

[sahdgrower]

I once saw a link to a youtube post where a guy used heat gun on the outside of the container while pressing on the inside with a round object right around your drain fitting (maybe a teacup) as the plastic heated up and with the pressure of the round object he deformed the plastic to make a little indentation on the bottom. All the water will drain here and you will have only 1/8 standing water in the area of the depression. I hope that makes sense. I have poured through volumes of info on these forums and cannot find the link.

 

[JamesFarmer]

I once saw a link to a youtube post where a guy used heat gun on the outside of the container while pressing on the inside with a round object right around your drain fitting (maybe a teacup) as the plastic heated up and with the pressure of the round object he deformed the plastic to make a little indentation on the bottom. All the water will drain here and you will have only 1/8 standing water in the area of the depression. I hope that makes sense. I have poured through volumes of info on these forums and cannot find the link.

AWESOME!!

Why didn't I think of that!!! I didn't even have to finish reading to understand exactly what you are describing. I am going to make a jig using holesaw and router then break out the heat gun.

If I don't F it up I will post pics.

Thanks for thinking outside the tub


FJ.

 

[budshoteyes]

If your table is fiberglass or wood the heat gun won't work,some other plastics won't melt!

Try;
Find or cut a four inch square plastic piece!

Then cut a hole for the bulk head in the four inch square piece of plastic!

The hole in the table should then be cut to the size of the top diameter of the bulkhead!

Place the four inch square with the bulkhead attached to the hole under the table,should fit nice and no bulkhead sticking out above the table....here comes the tough part;
Drill four holes for one eighth bolts...one for each corner of the square and the table at the same time!!!

Use water proof glue or gasket and or both to both the square and bolt holes....attach it and let dry. Done!

Stainless bolts and nuts preferred,their cheap and will never rust!
And use what ever size square...could be a round piece too...as long as it fits and can be bolted on....good luck!

 

[JamesFarmer]

If your table is fiberglass or wood the heat gun won't work,some other plastics won't melt!

Try;
Find or cut a four inch square plastic piece!

Then cut a hole for the bulk head in the four inch square piece of plastic!

The hole in the table should then be cut to the size of the top diameter of the bulkhead!

Place the four inch square with the bulkhead attached to the hole under the table,should fit nice and no bulkhead sticking out above the table....here comes the tough part;
Drill four holes for one eighth bolts...one for each corner of the square and the table at the same time!!!

Use water proof glue or gasket and or both to both the square and bolt holes....attach it and let dry. Done!

Stainless bolts and nuts preferred,their cheap and will never rust!
And use what ever size square...could be a round piece too...as long as it fits and can be bolted on....good luck!

Thanks for the suggestions. Being that the tub is made from polyethelyne using glues or sealants can be tricky as they don't adhere to PE.

I was able to use the idea offered by sahdgrower with good success.
I cut a 3" hole in a large scrap of 1/2" plywood, placed the tub on the plywood, heated the area above the 3" hole with a common propane torch then pressed down from the inside of the tub with a piece of 2" PVC pipe that I had rounded the edges over with a 1/4" round-over bit.

It made a nice "almost factory" indentation for the bulkhead fitting. Unfortunately the "almost" part caused me a bit of trouble. When I tried to reheat and make it "perfect" I tore the material. Instead of tossing the tub and buying another I decided to try "plastic welding". I cut narrow strips from another PE container and used them with the torch in a way that very much resembled brazing and managed to "weld" closed the hole that I made.

After it cooled I used a 2" hole saw to cut the hole for the bulkhead. Looks decent, doesn't leak and is mechanically solid.

Thanks again.

 

[budshoteyes]

Excellent! Good to know you've found a solution!
And... your welcome!