Airpumpless Sluckets

Growroom Design
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#11

Hi Larry. Rating for this pump with the needlewheel impeller (varios 6S) is 530 GPH. I unfortunately donā€™t have a good way to measure the actual flow rate or head at the moment (hmm, something to investigate). I could not find a chart specifically for this pump model. For the setup, actual liquid height over base is probably around a foot. From casual observation, flow looks sufficient but will circle around to this later for a measurement. The animated gif in the first post is from one of the buckets.

Replacing the impeller with a standard impeller (varios 6) produces 1720 GPH with a maximum head of 16 feet. The manufacturerā€™s chart for this one, for instance:

image.png800Ɨ800 213 KB

Here is an interesting blog post for potential uses for ORP monitoring: What is an ORP meter and why is it useful in hydroponics

ā€œThe chemical environment needs to have an ORP of above 600mV to eliminate harmful fungal spores and bacteria. Of course this means that if you want to run a sterile hydroponic environment youā€™ll want to keep the ORP of your solution probably in the 300-500mV range, large enough to prevent any micro-organisms from growing but low enough to prevent any damage from happening to your roots.ā€
ā€œThe ORP will also give you signs about water oxygenation and biological activity within the water. A reductive environment - ORP below 100mV - will mean that there is a significant number of substances in the solution that want to give electrons and these substances are generally organic acids, bacteria, viruses or other organics molecules, like reductive sugars.ā€

So possibly useful for a variety of situations. For instance, what happens to the ORP when one adds amino acids to the solution? How about beneficials? Can we tell if they survive or when they die off? Is it even measurable? How does this effect O2 levels? etc. I donā€™t know the answers to these. There is plenty of anecdotal evidence abound but not always enough empirical evidence. Would like to answer some of these or at least satisfy my curiosity. Growing something is actually a secondary goal for this platform :open_mouth: Blaspheme!

Yep, lots of gizmos around from my other life. They require some exercise in order to justify their existence :smiley:

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#12

Hear, Hear. Yep, simplicity would be the way to go! You are absolutely correct.

Though, Iā€™m hard headed at times and, as such, the actual intent and ambition in this case is to serve something a bit different. But, as they say, the best-laid plans of mice and men often go awry!

#13

Extra complexity ALWAYS comes back to bite you.

What does ORP stand for?

I use temperatures in the 60s and the waterfalls. Not only does it keep the system free of pathogens but even when I deliberately poured water from rotten roots into the system, nothing happened.

Iā€™m a much bigger fan of using natural processes to keep things in balance than poisonous chemicals.

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#14

Hello Ttystikk, the ā€œcomplexityā€ is quite intentional in this case. And yes, your system sounds like a well tuned machine. Not doubting it at all. Though, I will say that this thread is not about the use of poisonous chemicals.

ORP is a abbreviation for oxidation reduction potential, there is some additional description earlier in this thread. Similar to measuring PH.

#15

Iā€™m not here to criticise.

I think the addition of instrumentation is an excellent idea.

Thanks for the definition.

Can one increase the Oxidation Reduction Potential simply by continuous oxygenation via waterfalls, etc?

#16

Im a sucker for a cool gizmo or a project that lets me McGiver things together. I totally get the thinking behind your project. My current grow is much more of an experiment (an excuse to play with new gizmos) than it is a grow for the purpose of harvesting weed. It would be nice if I got some product at the end, but I already have enough RSO caps to last me into 2019. I mostly just wanted to play around with hydro :slight_smile:

I agree with you that simple is almost often better. I just cant resist messing with a good thing though :slight_smile:

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#17

If youā€™re getting that much flumming on all 4 buckets at the same time, it looks like enough to me. I would think that would give you close to 100% DO even without the needle wheel impeller.

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#18

It turns out that 100% saturation of dissolved oxygen is not hard to achieve. To increase absolute levels of DO, reduce water temperature. If my system temperature drops into the 60s at least once every 24 hours, it does fine.

The flip side of this is that allowing the water to warm up encourages higher metabolism and growth rates in the plants, all else being in order, of course.

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#19

Not at all, I get it. Thank you for the input. Just clarifying that there is a broader ambition that goes beyond growing at play. Hopefully, Iā€™ll be able to share some data in the future that someone would find useful. Some of which may simply be confirmation of general knowledge or maybe thereā€™s something that will be helpful for other experiments. In fact, I can envision times where Iā€™m purposefully stressing the plants.

In principal, yes. Though, an ORP probe is not selective for oxygen specifically and will instead detect changes in the reduction potential of a solution in general. It measures whether the solution has a tendency to acquire or contribute electrons, net positive or net negative at a specific point in time. Or, as a trend for on-going redox chemistry. ORP could be good at measuring DO at exceeding low levels (anaerobic conditions) but is not as precise for measuring elevated DO. A DO probe (or other analytical method) would likely be a better choice for measuring what would be the typical DO in a hydroponic solution.

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#20

Why do you want to eliminate the air pumps?

#21

That is my understanding as well. Will be measuring these things, too. Can adjust the flow rate and amount of air injected.

#22

One of the experiments, in progress. There have been past discussions on the use of needlewheel pumps to serve a dual purpose. Though, not a whole lot of follow-up with empirical data that I could find. Data forthcoming.

Ttystikk noted waterfalls which have been reported as one of the most efficient mechanisms. Flooming as an option as well. One benefit include not needing a separate air pump(s) and stones, among others.

Do you feel air pumps/stones are necessary or, more specifically, could be something that might be used as a point of comparison? Rate of O2 uptake higher than generally thought? Hint, hint: collecting compelling reasons to run an experiment :wink:

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#23

Im at least a few decades behind the latest thinking, but back when I was doing reef tanks, fluming and water falls were both considered far superior to your typical aquarium air stones for aeration. Pin wheel pumps with air injection/venturis and the whole ā€˜micro bubblesā€™ thing came along after I got out of that hobby.

I suspect that fluming and waterfalls will still be pretty much equal to any version of micro bubbles as far as reaching 100% DO, but thats just a guess on my part.

Im looking forward to more of your results!!!

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#24

Reefers gave me the confidence to build my waterfall driven system. It has worked faultlessly ever since.

Recently, my chiller failed. Even with water temperatures hitting the mid 70s, the water is clean and roots are healthy. If anything, the plants are growing weā€™ve faster!

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#25

Would you happen to have a photo of what the waterfall portion of your set-up looks like?

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#26

Yes, there are a lot of interesting differing techniques out there.

The micro-bubble thing is interesting but the origin of the term, I believe, had to due with bubble size that is exceedingly small. Using specialized equipment. So small, in fact, the bubbles are almost not visible and stay in solution for quite awhile (which could be good if recirculating through a large volume of solution). There are some research papers floating around and some you-tube videos but the equipment to produce what they are doing is fairly pricey. I think they were claiming that they
would achieve supersaturation using this technique some how. The term has seemingly been usurped by other experimenters to mean bubbles that are something smaller than what airstones would produce by using venturi and such. In this case, we would not see supersaturation. So, the term seems a bit muddied.

Then there is the whole hydrolysis thing. Also interesting but with the downsides of decreased
reliability, reliance on power, cost, and the unclear effect of using such a set-up.

It seems that the aquarium folk probably have some of the most accurate results and overall
experience simply due to them being particularly sensitive to maintaining DO levels.

From what I can recall from memory, there was an individual on another forum that ran a set of experiments some time ago comparing the different aeration techniques. I think he came to the conclusion that the waterfall technique produced the highest level of saturation. Fluming was nearly equivalent. And, airstones were somewhere lower on the list. Still sufficient but lower. I have not seen similar tests (that were as thorough) backing his conclusions but the anecdotal consensus is that his results are accurate.

I have an optical DO probe and Iā€™ll measure what Iā€™m seeing here once I get this thing built out fully. Will be fun!

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#27

I run an RDWC system. Think of an Undercurrent, only the recirculating pump is in the control bucket (ā€˜epicenterā€™) and it feeds a manifold that delivers water directly to an elbow fitting in the lid of each tubsite. That water drop is the waterfall.

Water then runs via gravity back to the control bucket through lines near the bottom of each tubsite. The control bucket also has the coil for chilling the water.

I did it this way after noticing that in a standard Undercurrent system, the best oxygenated bucket was the only one they didnā€™t want you putting plants in!

Having a waterfall in the lid means that there is more churning and movement in the bucket for the roots. It automatically oxygenates. It breaks surface tension, preventing any surface scum from forming. The splash wets the bucket so the plant gets watered no matter what the water level is, making water level much less of a factor.

My chiller has been down for a month and my plants are healthy. Apparently this approach even eliminates the need for chilled water, which to me is an amazing benefit!

Iā€™m going to copy this post into my own thread to explain the waterfalls to those who are reading there. Youā€™re more than welcome to check it out, itā€™s here:

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#28

Supersaturation is nice but unnecessary.

In fact, as demonstrated above, air pumps are also unnecessary. And air stones. And the lines to connect them.

These are all systems designed to correct for weakness in the fundamental design- as I hinted above, the Undercurrent system is flawed- or just something else for hydro stores to sell to the customer.

Mother Nature doesnā€™t need supersaturated water for the roots, why should we need it to grow plants that are anything but exotic?

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#29

Hi man; looks like you think a lot like me: less = more. I ordered a Slucket system but suspect they e gone under since their site is dark and they arenā€™t responding to order questions. While I deal with that mess; going to just DIY it. Question: where is your drain located?

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#30

@CatalystX, check out Ttystikks set-up at the following link if you have questions on how he has his system set-up: Vertical farming @Ttystikk

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