Undecurrent DWC Plumbing Questions

Hi Everyone,

I'm a longtime lurker of the boards but this is my first time actually posting. Up to this point I've been able to find answers to all my questions by reading other posts. Anyway, I'm running into an issue in the design of my new 4 bucket undercurrent system. I know that with a UC RDWC system it's best to use large diameter (2"+) PVC to connect all the buckets to the controller to prevent roots from clogging the lines. But, it would be much easier, cheaper, and quicker to build the system connecting the buckets using 1" flexible hose. Am I definitely going to get a clog if I do this? What other drawbacks are there? I don't plan on vegging the plants longer than 2 weeks and they will be in 5 gal buckets.

If it's worth it, I'll deal with the hassle of working with pvc and uniseals. But if the 1" hose is sufficient for a 4 bucket system I'll roll with that. Any help would be appreciated. I've read many undecurrent grow journals and I haven't seen anyone using the 1" flexible hose yet so I'm curious if anyone has completed a grow with it. Thanks in advance.

Also, I haven't purchased a water pump yet. I'm not sure if that makes a difference in what size plumbing I use but I'm open to suggestions there as well. I'm planning on a 700 GPH danner.

Isn't there like tray's that can be placed on the bottom so the roots don't reach the drain? I'm curious about this myself.

Yes, 1" is sufficient. I use it myself and it works better. I started out using 2" pvc and then the roots clogged up the pipe and I got leaks from the uniseals which caused a lot of frustration. So, after two uc systems with pvc, I built my own from 1" tubing. I run TWO lines through the bottom of the buckets and I use the 1" ebb/flow drain pieces with the screen on the inside of the bucket to stop roots from clogging. You also with have to clamp (metal clamp) the tube to the drain piece or it will leak at the connection. Its a little more pricey than the PVC BUT you can easily change out buckets and they move with no problem. I currently have 2 systems (8 gal and 13 gallon) going with 1" hoses connecting my buckets. (13 gallon has 3 lines going to each bucket).

The uniseals blow nuts to work with but my first attempt was 3/4" hose and my water pump was sucking water from the last bucket, but the hose wasn't big enough to allow water to rush into the bucket so it would end up sucking the bucket dry. I think you would need to be careful what size water pump you have or you will just suck the return bucket dry with too small plumbing.

You have to match your fitting with the pump size. If you use small tubes and too big of a pump, water will fill the bucket faster than it can drain into the next, and you will have overflows

This is exactly what I was trying to figure out. So how do I determine what size pump I need if I use the 1" hose? Is there an equation or something?

Themlouds, thanks for the tip on the ebb/flow screens, that's a great idea. Can you give me a few more details on your setup? It sounds very similar to what I'm trying to do. How many buckets total do you have and what size is your pump?

Thanks everybody!

I doubt it the grand scheme of things that 2" pvc and uniseals will be much more expensive then 1" bulkheads and decent quality opaque flexible tubing. If you must... Silicone a netpot over the bulkhead to act as a screen. I use the 700gph magdrive it gets really hot. I have a chiller, if you don't then I would get a smaller pump depending on the total volume of water in your system, mine is 100gal. If your only running 4-5 5gal buckets a 700gph is way overkill and will just lead to problems. There are way better pumps then magdrives that move more water for less watts (heat) but they are triple the price. Check out my system, it could give you some ideas and since it uses 1 vessel for 2 plants it cuts down on uniseal cost and is pretty customizable.

I would highly discourage from using hose. The diameter is not big enough to produce a true undercurrent.
There is a reason why they are designed the way they are, and it's about results, not taking the easy route.
I just built my own UC 6XL modified replica, and the uniseals are not difficult. Anyone who gripes about them
is probably lazy and didn't do things carefully.

Silicone the uniseal to the bucket, and use KY jelly/lube to carefully slip the piping into the uniseal.
I haven't had a single issue with leaking with my DIY setup. Using too small of hose will likely clog
and then it's no longer an undercurrent, and may lead to root pathogen issues. A chiller would be
a very good idea.

Also, on the return line, an inline filter would be highly recommended. Yes, it can clog. Why? Because
it's filtering out grabage that could damage your pump. I clean mine with a toothbrush once a week
or whenever I notice reduced flow.

If you want, in the grow log in my signature, I posted a video showing how my system works.

poopstain2 said:

I doubt it the grand scheme of things that 2" pvc and uniseals will be much more expensive then 1" bulkheads and decent quality opaque flexible tubing. If you must... Silicone a netpot over the bulkhead to act as a screen. I use the 700gph magdrive it gets really hot. I have a chiller, if you don't then I would get a smaller pump depending on the total volume of water in your system, mine is 100gal. If your only running 4-5 5gal buckets a 700gph is way overkill and will just lead to problems. There are way better pumps then magdrives that move more water for less watts (heat) but they are triple the price. Check out my system, it could give you some ideas and since it uses 1 vessel for 2 plants it cuts down on uniseal cost and is pretty customizable.

Click to expand...

Thanks for the tips! I like the idea. So what type of pump do you think I should get instead of the magdrive? I'm willing to spend more money on the front end to make sure I do this the right way.

LivingCanvas said:

I would highly discourage from using hose. The diameter is not big enough to produce a true undercurrent.
There is a reason why they are designed the way they are, and it's about results, not taking the easy route.
I just built my own UC 6XL modified replica, and the uniseals are not difficult. Anyone who gripes about them
is probably lazy and didn't do things carefully.

Silicone the uniseal to the bucket, and use KY jelly/lube to carefully slip the piping into the uniseal.
I haven't had a single issue with leaking with my DIY setup. Using too small of hose will likely clog
and then it's no longer an undercurrent, and may lead to root pathogen issues. A chiller would be
a very good idea.

Also, on the return line, an inline filter would be highly recommended. Yes, it can clog. Why? Because
it's filtering out grabage that could damage your pump. I clean mine with a toothbrush once a week
or whenever I notice reduced flow.

If you want, in the grow log in my signature, I posted a video showing how my system works.

Click to expand...

Dude, your setup is awesome! That video was incredibly helpful. Love how you designed the return line with the stop valves for easy nute changes. I'll have to steal that idea. Where did you get your ez stor buckets? I've read those are much better for uniseals than buckets.

Here is one that moves 634gph at half the wattage of the danner (30 vs 60).

[url]http://www.marinedepot.com/Tunze_Recirculation_Pump_Powerhead_Silence_Fixed_Flow_Aquarium_Powerheads-Tunze-TZ1737-FIPHFF-vi.html
[/URL]
Water blaster pumps are nice too 550gph@22watts all the way to 1300gph@60watts the same wattage as the magdrive.

http://www.coralvue.com/water-blaster-pumps

Don't get me wrong magdrives are cheap reliable workhorses but they are pretty inefficient. You could put the extra money saved by buying the cheaper magdrive toward a type of chiller. If money is no object get a water blaster and a type of chiller.

Hello, I am gathering the materials to build wexactly what you've described here. I don't want leaks or even a chance, I want to be able to rotate out / in buckets if I want to clean them one at a time without tearing it all down, just having one extra made bucket so if I want I can rotate one out like you said. I don't understand exactly how you have the buckets connected? I get the ebb and flow fittings but how do you connect the hose to the fitting and the fitting to the bucket? can you help me with pics and details maybe? This is whats stopping me from proceeding. May I ask where you get your black 1 inch hose and fittings?