Quick Question on DIY Under Current

elrodvoss

Well-Known Member
Looking at making a under current system for my 4-6 bucket grow.

Is there any issue I may have with using 1 inch pipes rather then 2 inch? I am also using 5 gallon buckets vs 8 gallon.

Thanks as always for advice.
 

rkymtnman

Well-Known Member
i'd use square pails not round buckets. less chance of a fitting leaking on a flat vs round surface

2" moves more water=better results. the faster you can move the oxygenated water the better.
 

Darth Vapour

Well-Known Member
i'd use square pails not round buckets. less chance of a fitting leaking on a flat vs round surface

2" moves more water=better results. the faster you can move the oxygenated water the better.
This is not necessarily true one has to figure all the gear that is going to be used ,, figure out head pressure , resistance loss pressure and so on for every foot of pipe there is loss friction so many factors are involved and what many forget to work on for 100 percent efficiency flow etc angles everything has to be really figured out
 

rkymtnman

Well-Known Member
This is not necessarily true one has to figure all the gear that is going to be used ,, figure out head pressure , resistance loss pressure and so on for every foot of pipe there is loss friction so many factors are involved and what many forget to work on for 100 percent efficiency flow etc angles everything has to be really figured out
UC is not rocket science. a 2" is always better than 1" pvc. and a uniseal will always work better on a flat vs round surface.
 

elrodvoss

Well-Known Member
Well i dont have the pump picked out yet, but i do have 1 inch bulk head fittings and haves used them before with fish safe silcone before and never had a leak. Just trying to avoid buying more material, if what i have would work.



I know there are cheaper ways other then bulkhead fittings, but for me they are much better in ways of leak proofing.


I dont grow trees with this setup and dont plan on having get taller then 4-5 feet before harvest.


I know bigger is better, but would this be ample.
 

elrodvoss

Well-Known Member
Please parden if i came off snippy. I know there are unknowns (pump size), just want to mock up the buckets and get them ready and if 1 inch will not fill my needs, then i need to order up 2" fittings to make it work.


And at harvest, these may be 3-4 tall, not 4-5.


Again, thats for input and help.
 

Darth Vapour

Well-Known Member
One of the really hard to grasp principles of hydraulics is the relation of volume of flow, pressure, and the weight of water. Odd as it seems a larger pipe will actually be easier for the pump. It’s not the volume of water, but the height it is lifted that matters. In a way this is a variation on the old saying “which weighs more, a pound of feathers, or a pound of lead?” Obviously both weigh a pound! This version could be phrased “which is easier for the pump, 5 GPM in a 1/2″ pipe or 5 GPM in a 2″ pipe? Neither because 5 GPM is still 5 GPM regardless of the pipe size! Yes, you would need more power if you were actually lifting more water, also we would need more power to lift the water higher, but neither is not what is happening. The amount of water nor the height we are lifting hasn’t changed.
 

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Darth Vapour

Well-Known Member
Think about feet of head. the number of feet of water depth determines the water pressure. So 80 feet of water depth equals a pressure of 80 ft. hd. This pressure will be the same regardless of the pipe size. The water pressure at the bottom of an 80′ high 1/2″ pipe is exactly the same as the water pressure at the bottom of an 80′ high 6″ pipe, even though the 6″ pipe holds a lot more water. A pump actually works by creating water pressure. So for the pump there is no difference between pumping into either size pipe, the water pressure required to move the water into the bottom of both pipes is the same. Now the pressure lost as water moves through the two pipes will be different. Assuming a high rate of flow, a lot more pressure will be lost due to friction in the smaller pipe. So for that reason using a larger pipe will be better. Depending on the flow, however, it may be only very marginally better. To find out you need to calculate the friction loss in the outlet pipe based on the flow and pipe size.
 

ttystikk

Well-Known Member
Well i dont have the pump picked out yet, but i do have 1 inch bulk head fittings and haves used them before with fish safe silcone before and never had a leak. Just trying to avoid buying more material, if what i have would work.



I know there are cheaper ways other then bulkhead fittings, but for me they are much better in ways of leak proofing.


I dont grow trees with this setup and dont plan on having get taller then 4-5 feet before harvest.


I know bigger is better, but would this be ample.
Your bulkhead fittings will work fine on standard five gallon buckets. I've done plenty, they're fine. One inch tubing will be sufficient as long as you don't go more than three or four buckets in a row. Beware there is always a step down in water height for each bucket, so the first bucket will have a higher water level than the last in any given run. The bigger the circ pump, the more pronounced this step will be, which argues for a smaller pump!
 

ttystikk

Well-Known Member
Think about feet of head. the number of feet of water depth determines the water pressure. So 80 feet of water depth equals a pressure of 80 ft. hd. This pressure will be the same regardless of the pipe size. The water pressure at the bottom of an 80′ high 1/2″ pipe is exactly the same as the water pressure at the bottom of an 80′ high 6″ pipe, even though the 6″ pipe holds a lot more water. A pump actually works by creating water pressure. So for the pump there is no difference between pumping into either size pipe, the water pressure required to move the water into the bottom of both pipes is the same. Now the pressure lost as water moves through the two pipes will be different. Assuming a high rate of flow, a lot more pressure will be lost due to friction in the smaller pipe. So for that reason using a larger pipe will be better. Depending on the flow, however, it may be only very marginally better. To find out you need to calculate the friction loss in the outlet pipe based on the flow and pipe size.
You're right, but this is waaaay too complicated for the task at hand, LOL
 

Darth Vapour

Well-Known Member
i like 2 pump systems where you can service a pump whlle other is online and vice versa also its more efficient to the op get in line pumps not submersibles that will create water heat
 

ttystikk

Well-Known Member
i like 2 pump systems where you can service a pump whlle other is online and vice versa also its more efficient to the op get in line pumps not submersibles that will create water heat
My submersible pumps don't create much heat and they last a lot longer in the water where they stay cool. I use just one in a system, so less complexity.
 

ttystikk

Well-Known Member
So look, this guy named Heath Robinson was doing the very same RDWC thing ten years ago, only he ran top feed into hydroton in netpots over water in tubs or buckets. It worked then (he's a bit of a legend, grew monsters) and it works now- and it's much simpler; right off the bat, you can lose the air pump, airstones and lines! Yep, they're totally unnecessary... Next, make a manifold that constantly runs water thru your netpots full of hydroton. Hook your pump up to that, and drop the pump into the 'epicenter', aka control bucket, and put your cold coil in there, too. DONE. Now go grow some fuckin' trees already, willya?!
 

bicit

Well-Known Member
So look, this guy named Heath Robinson was doing the very same RDWC thing ten years ago, only he ran top feed into hydroton in netpots over water in tubs or buckets. It worked then (he's a bit of a legend, grew monsters) and it works now- and it's much simpler; right off the bat, you can lose the air pump, airstones and lines! Yep, they're totally unnecessary... Next, make a manifold that constantly runs water thru your netpots full of hydroton. Hook your pump up to that, and drop the pump into the 'epicenter', aka control bucket, and put your cold coil in there, too. DONE. Now go grow some fuckin' trees already, willya?!
This, RDWC is much simpler to setup than a UCDWC. Personally I skipped hydroton(no media at all actually) and used misters for a pseudo aeroponic setup. Don't know how effective this is vs running it over hydroton though.
 

ttystikk

Well-Known Member
This, RDWC is much simpler to setup than a UCDWC. Personally I skipped hydroton(no media at all actually) and used misters for a pseudo aeroponic setup.
Oh boy is it ever easier, because one inch bulkheads fit one inch FLEXIBLE tubing! No more PVC pipes to cut and fit!

The hydroton is there for the watering and for the roots to hold onto something. It is reusable indefinitely, I barely even bother to rinse it.

I don't run mister style systems as I hate clogs.
 

redi jedi

Well-Known Member
Looking at making a under current system for my 4-6 bucket grow.

Is there any issue I may have with using 1 inch pipes rather then 2 inch? I am also using 5 gallon buckets vs 8 gallon.

Thanks as always for advice.
Just make sure your suction line to the pump is no bigger than 1/2" Otherwise you will have unequal water levels in your buckets.

I would recommend 1-1/4" or 1-1/2" PVC. To allow for a bit of blockage from roots.
 

bicit

Well-Known Member
Oh boy is it ever easier, because one inch bulkheads fit one inch FLEXIBLE tubing! No more PVC pipes to cut and fit!

The hydroton is there for the watering and for the roots to hold onto something. It is reusable indefinitely, I barely even bother to rinse it.

I don't run mister style systems as I hate clogs.
I hate messing with hydroton in all honesty. I use 2 inch netcups and collars for clones, no media. 2" netcups with Rapid rooters for seeds. The netcup is usually enough to support it. Though I just wish that the lips on the edges of the netcups were a bit wider, since occasionally with unsupported bushes can fall through the lid.

Misters only really serve to oxygenate the solution and sustain the plant 'till roots hit water. I prevent clogs by having a wire screen inline with the pump, even if a mister clogs, it's usually not the end of the world unlike in a true aeroponic setup.

Though to be fair, I still prefer straight DWC in 3 gallon buckets with airstones. I'm looking at passive systems like coco+blumats right now though. Then I can just hook it up to the RO machine and call it a day.
 
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