Replacing air stones with waterfalls in RDWC

Funkadelic said:

Ty stick, I'm surprised more that you haven't been fluming for years now. You're quite a clever fellow.

Yep, h20 returns can provide rich tdo. But then I'm a soil and aquarium guy.

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I looked into that approach some time ago and it didn't solve any more problems than airstones did. The reason this method has me excited is because the splash and churn is as beneficial as airstone oxygenation in each site, then further aids the environment under the lid and above the waterline and finally pushes water around inside each tub to circulate it past the roots.

The fact that I've done this while only going up from 396 gph to a 633gph water pump, AND thrown out the entire air system from pump to stones is what has me pumped!

ttystikk said:

I know baked! Sounds like his and mine share some similarities. Mine is a more straightforward 4 tub 27 gallons each RDWC, so not quite like a flood table. Mine has an enclosed lid, flood table doesn't.

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kootenainatural said:

Ya his tables come with tops he drills 5 inch holes in em for net pot to sit in then the roots dangle from those to the water but il get him in here you guys can chat it up he's a good dude

Much respect
Kootenai

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I get the table tops...they are available for all botanicare tables. I run 2 x 4 tables and some 3 x 3 tables with lids. I use a 3.25"' hole saw to make my holes. Plants are then put in 3.75" net cups filled with hydroton/clay and just set in table lids.

Here is a pic of an under the lid peek...

This is a 2' x 4' table...


This is a shot while cleaning out the table....typical root ball from a 2 x 4 table....continuous flow

ttystikk said:

If his flood table has a lid, then just continuously running the fill pump and letting excess water drain back through the return/overflow will oxygenate the system just fine. I've heard about issues with trying to oxygenate a 'dead reservoir' style ebb n flood, but I bet they would be solved with a continuous flow approach.

One thing I would change if I were to run this is that in my ebb n flood trays, the inlet and overflow are right next to each other. I'd relocate one of these to the opposite side of the table, so water would flow across and ensure all plants see fresh nutes.

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Here are some better shots to understand for ya...

from outside here is the table with a roughneck under it...notice the 1/2' and 3/4' hoses...one fill one drain...this is a 3' x 3' Botanicare table...with a 31 gallon Roughneck.


this is what's going on in the ressy... 396 gph pump running


this is what's going on inside the table...if you look at the first pic here...on the right is the drain...the left is water pumping in...now since they are side by side to aide in making sure it's all mixing well I cut a little piece of 1/2" hose and put a 1/2" 90 on it to ensure the pump fires at the back of the table and drains forward. The hoses being up front and side by side just simplifies the water changing process and cleaning for me...





A rather simple design...but effective for me!

I saw what you said about putting the inlet and the drain on opposite ends...in the perfect world this would be great. I have ran that way having an attached line out of reach is a pain. The cleanup in between runs became a pain also....cuz I like to clean all lines out in between runs. I solved my mixing issues with a bent 90 shooting at the back of table...while the drain is in the front...check pics. Really simplified everything for me when I put them together like shown...

I would like to see the pics of your design....I have made many home made designs over the years...it sounds similar to one I have built before...but I would like to see pics. How are you draining back to main tub?

@BakedReality NICE! Amazing roots! The trick of putting a 90 degree elbow on the pump inlet works fine, obviously.
Do you ebb n flow, or is it continuously running?

In my case, I'm running the very same 3x3 Botanicare tables you are, only they are in my veg area. The lid thing would work well for one of them, but for the one where I have a bunch of small rooted cuttings it would not work out well.

Continuous flow...always running...24 hours. I do 31 gallon roughnecks for my 3 x 3's...usually running 20 gallons. On my 2 x 4 tables I use the 18 gallon roughnecks...usually running 17.5 gallons.

I am not sure why smaller rooted cuts wouldn't work with a lid. I use the same size whole saw and and net cup for every stage of growth...this way everything is interchangeable. I just move the net cup....

I would have to see some pics of your set-up...to understand. I guess I didn't understand you ran tables.... so you had botanicare table before with just air stones? no ressy?

Hope all is well. Good Luck shaking the flu....

BakedReality said:

Continuous flow...always running...24 hours. I do 31 gallon roughnecks for my 3 x 3's...usually running 20 gallons. On my 2 x 4 tables I use the 18 gallon roughnecks...usually running 17.5 gallons.

I am not sure why smaller rooted cuts wouldn't work with a lid. I use the same size whole saw and and net cup for every stage of growth...this way everything is interchangeable. I just move the net cup....

I would have to see some pics of your set-up...to understand. I guess I didn't understand you ran tables.... so you had botanicare table before with just air stones? no ressy?

Hope all is well. Good Luck shaking the flu....

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My 'bullpen' table is for holding small moms and taking just rooted cuts. This is where I match up plants and send them on as a group, so the number of plants is constantly changing.

The other 3x3 is further along in veg and will take only the number of plants I send through as a group. Currently four, might move to eight plants. When I have a better handle on how many I want to run in a batch, I'll get a lid and saw some holes.

Both of these stages are run as standard ebb n flood tables, filled twice a day for 15 minutes each.

The next stage from the 3x3 is an RDWC under a MH thouie, this is the final prebloom veg stage. The next upgrade will see this get its own room so I can run it as an early bloom stage for those strains that need more than 8 weeks to run.

Hope you get over that flu sooner than later bud. You are helping me save a grip of money. I used to run 2 AP-100's for a 12-site UC and $30 micro-pore diffusers in each bucket. LOL at $3 air stones. To think I could have been using one 1800gph mag drive to recirculate and oxygenate every bucket!! Epic win for us water culture nerds!! Anxiously waiting the pics. Thanks for your contributions my dude. I'm definitely picking up the gems you're dropping -Keepz

Okay, pics first, then discussion;

All those who took hydrodynamics in college can skip to the next post- for the rest of us, what is essential is to carefully manage the size of your lines. As I said above, the Pex manifold didn't work because its openings were too small, making it the restriction that determined flow rate.

It's all about cross sectional surface area; pi x radius squared of the inside diameter of your pump outlet, main line, any and all fittings and finally outlet size. It's a funny thing, but the cross section of four 1/2" lines is exactly the same as the cross section of one 1" line- and this is important, as it means that you can get a good flow rate with this ratio.

Trying to overcome a built in flow restriction by oversizing your pump is not gonna work out well, because water is an incompressible substance- that is, you can't squeeze a given volume into a smaller space. This is the principle hydraulics is based on. Once you've introduced the restriction, all flows downstream are limited by it, or to put it another way, you never get your flow back.

SO- no matter how you do this, make certain that the smallest orifice is always the one shooting water into your tub.

To solve the Pex manifold problem, I perused the irrigation parts section of my friendly neighborhood hardware store and found the Blazing Saddles line of fittings. The pieces pictured are the 1" poly tee fitting with a 1/2" feed, and an end cap with another 1/2" feed- or a simple 1" plug.

Each feed from its own tee fitting comes from the main supply and several are connected with short bits of 1" hose. In this way, I eliminated the flow restrictions associated with the Pex manifold because now the holes get progressively smaller from pump to outlets, just like they're supposed to.

At first, I ran a 1340gph pump- and it blasted water through and into the tubs! The 633gph unit didn't blast as hard but it was enough to oxygenate, churn and splash sufficiently to give my girl's roots something attractive to peek out from the bucket and eventually into the RDWC water below.

Those fittings are meant for high pressure sprinkler applications so the multiple o-rings are plenty for our purposes. If you value your hose, do not press it on over the green lock ring- you'll need to cut it off if you do.

Now, I did this for a 4 tub RDWC, so while the concept is the same for larger numbers of sites, it will take some work to figure out how to effectively scale this up. One option could simply be to run three pumps with four outlets each.

The girls I'm running in these tubs look GREAT!

Couldnt't you use a manifold like this:

twist1 said:

Couldnt't you use a manifold like this:

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In my case it wouldn't be effective, as the main barrel appears to be only 5/8" inside like garden hose. This would create the same restriction as the Pex manifold I mentioned earlier.

Perhaps throwing a bigger pump at it would suffice, but that creates an issue of potential excess heat in the water.

The key seems to be having a large inside diameter of the main line through whatever you use as a manifold. Whether the products from that main line are smaller our not doesn't matter- as long as they're bigger than the opening size you use at the tub site.

ttystikk how about complete system pics and action shot?
plz;)

The beauty of the system is its simplicity- those two pics above are really the system. There's a half inch elbow fitting at the other end of each of those half inch lines, and they aim the water down into the tub water- exactly like peeing in the toilet, lol

I understand that waterfall mixes the most oxygen but im suprised that a pee stream is enough to oxygenate.good stuff. are those 5 gal buckets?

larebowm said:

I understand that waterfall mixes the most oxygen but im suprised that a pee stream is enough to oxygenate.good stuff. are those 5 gal buckets?

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The pee stream comment was meant for comparison about how it works, the intensity of the stream certainly does affect its effectiveness. The oxygenation is the easiest thing to achieve; what I'm aiming for with this setup is more agitation of the water, more splash and humidification of the space inside the tub above the water.

The sites are 27 gallon tuffboxes from home dePot, with a circle cut out of the lid such that a collar from a homer bucket just fits. This allows my netpot bucket lids to fit securely, keeping moisture in and light out. Building my system around netpot bucket lids makes it trivially easy to move plants from place to place, which them allows me to build spaces for each stage of plant development that are perfectly suited- and when the plants outgrow it, I carry them to the next carefully designed space!

to get a little more water fall effect you could take a tee and cut a small slit from end to end of the long part and cap it, instant water fall? Water drops out of the slit = more surface area disturbed. I just pulled my pond aerator that came with my UC for this run and just have the air line bubbling up.

woodsmaneh said:

to get a little more water fall effect you could take a tee and cut a small slit from end to end of the long part and cap it, instant water fall? Water drops out of the slit = more surface area disturbed. I just pulled my pond aerator that came with my UC for this run and just have the air line bubbling up.

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I'm thinking something even simpler; a short length of 1/2" tubing with a cut down the side of it and plugged at the end. Water then sprays through the slit cut down the tubing.

That might give up some underwater agitation, but I don't know if it's significant.

ttystikk your inspiring me to make a change what size plant can be expected from five gallon buckets.
yield?although i understand many variables.