Ideas on DYI water cleaning? Want to reduce waste water...waste

Hey everyone,

I’m kicking around some ideas for winter projects, and I stumbled across this article from Royal Queen Seeds about reusing water in hydroponic systems (link: https://www.royalqueenseeds.com/blog-how-to-clean-and-reuse-the-water-from-your-hydroponic-system-n1030). It got me thinking about DIYing a system to clean and reuse water—maybe using ozone or UV light.

I did some Googling, but didn’t find much on how to build something like this yourself. I’ve seen some UV systems out there for $200-300 CAD, and some higher end for much much more. I’d rather put that money (or less if possible) into making my own setup if I can, learning new things has been a major part of this new hobby.

Here’s what I’m thinking, but this is from my experience as a pump room guy for the community pool (the RDWC concept is so similar to how a pool filter room would work):
  1. Filtration:
    • Start with a basic mechanical filter to catch bigger stuff—thinking layers of mesh, carbon, and gravel.
    • Add a biological filter with some beneficial bacteria to break down organic gunk. (I have done zero research into this, chlorine and biological...).
    • For sterilization, maybe a DIY UV-C light setup (around 254 nm) to zap bacteria and algae.
    • Or, go with an ozone generator and a DIY injector to oxidize and clean the water—just need to keep the ozone levels in check.
  2. Recirculation:
    • Figure out how to connect it back to my hydroponic setup, either straight to the reservoir or a holding tank.
    • Maybe something i could disconnect and only connect when i need it or need to sanitize the whole system.
  3. Automation (Optional):
    • If I’m feeling ambitious, maybe add some sensors to monitor water quality (pH, EC, ORP) and automate things using Arduino or Raspberry Pi.
  4. Safety:
    • Make sure I handle ozone and UV light safely—keep everything contained and well-ventilated.
    • this is my biggest concern both those things can be super dangerous if you are being stupid.
This is just the early planning stage, so I’m wide open to ideas. Has anyone here tried something similar? I’m all ears for any tips or experiences. The goal is to reuse as much water as possible and keep things running smoothly with my current hydroponic setup.

Thanks in advance!
 

:idea:

Apologies, long weekend up here in the great white north. This is such an interesting idea, I would never have thought of using a centrifuge to filter.

got some concerns that ill need to read up on:
1. moving parts: there is a lot of force that goes into spinning those fast enough to make it useful. I'm worried about wear and tear/replacement part costs.
2.overall cost of a centrifuge: i know its beyond my skills to make my own centrifuge, so ill have to buy one. what size, RPM, would i need to make this worthwhile and cost effective.

ill post when i come up with number and items but I'm not even sure what data i need to find to be able to calculate this...im going to whiteboard this when i get home from work and see what i can come up with.

thank again for this I'm going to at the very least understand centrifuges after this.
 
Your DIY project sounds exciting and innovative!
Well, thank you! I’m really glad to hear that people find this project interesting, especially coming from someone at a company known for innovative, high-quality products!

I think I’m going to need to narrow down my goals a bit—it’s already starting to feel a little daunting. Your feedback definitely helps keep the motivation up.

I’ll keep you all updated, and if you have any more feedback or ideas, feel free to send them my way!
 

Mumbeltypeg

Well-Known Member
Enzyme filter rings a bell.. I believe they use something like that in the large aquaponic setups before recycling the water for the fish. Might be worth having a look into.
 

7CardBud

Well-Known Member
Run a triple RO in series, then use the super concentrated wastewater to flush the commode once a week.
The RO water is ready for fresh nutes and you saved a flush of water as well....win win.
 

Greenman68

Active Member
UV filtration as recommended by this guy, a chemist and a colleague of bugby, he also addresses ozone


This setup sounds like it will be very cool so please post updates! I would love to know how to make a DIY UV filter.
 
Run a triple RO in series, then use the super concentrated wastewater to flush the commode once a week.
The RO water is ready for fresh nutes and you saved a flush of water as well....win win.
That’s definitely elegant in its simplicity! I’d like to avoid flushing just for the challenge, but great suggestion.

On a more serious note, I don’t think reverse osmosis (RO) will work effectively on its own, but I do believe it will need to be part of the overall system. Let’s bookmark the idea of an RO 3-stage setup for part 2 of this project. More to come!
 
UV filtration as recommended by this guy, a chemist and a colleague of bugby, he also addresses ozone


This setup sounds like it will be very cool so please post updates! I would love to know how to make a DIY UV filter.
AMAZING! Thank you so much. I’m at the sponge stage, so any quality info is fantastic! I can’t wait to watch this tonight.

Apologies if this seems a bit disjointed, but I’m just laying out my thought process (the PG-rated part at least), and a lot of it will probably end up in the “use that info later” bin.

Here’s what I’m trying to learn and what I’ve picked up so far:

1. UV Light Exposure Time:
  • UV Dose Calculation: The effectiveness of UV sterilization depends on the dose, which is the product of UV intensity (measured in mW/cm²) and exposure time (measured in seconds).
  • Intensity of UV Light: intensity of your UV light and the flow rate of water through the system. (use AI to compile market averages)
  • Exposure Time: Calculate the time water needs to stay within the UV light’s path to receive an adequate dose. adjusted by controlling the flow rate through the system.
2. Timing Before Pump Out:
  • Flow Rate Control: calculate the flow rate to ensure water spends enough time under the UV light.
  • Holding Tank or Bypass: secondary holding tank or bypass tank a must.
Steps to Calculate Timing:
  1. Determine the Required UV Dose: Research the required UV dose for effective sterilization of the most common contaminants in hydroponic water. (done for drinking water)
  2. Measure UV Light Intensity: Find the specifications of your UV light (mW/cm²). I have lots of emails out to manufacturers, no responses yet.
  3. Calculate Exposure Time: Exposure Time (seconds) = Required UV Dose / UV Intensity.
  4. Adjust Flow Rate: Ensure that the flow rate allows each gallon of water to receive the necessary exposure time before being pumped out.
Preliminary Calculation of UV needs: 30 MW/cm2 sample number
  • UV Intensity: 30 mW/cm².
  • Required Dose: Let’s assume a required dose of 60 mJ/cm² for effective sterilization.
  • Exposure Time Needed: 60 mJ/cm² / 30 mW/cm² = 2 seconds.
Each gallon of water must spend at least 2 seconds under the UV light. Adjust the flow rate or incorporate a holding mechanism if necessary. Bearing in mind that 30 mw/cm2 is the high end of the UV-C light ranges my budget will have me with most likely a UV-C 10to 20. Water exposure will likely need to be 4-6 seconds.

  • Lower-end consumer UV-C lights: around 5 to 10 mW/cm².
  • Mid-range consumer UV-C lights: 10 to 20 mW/cm².
  • Higher-end consumer UV-C lights: 20 to 30 mW/cm² or more.


Problem: flow controls

Next Steps:
  • Determine the approximate UV light power .
  • Calculate the required exposure time based on the intensity of your UV light.

I finally found something that fits my mental image of this over at Vevor.to be honest at that price im going to be hard pressed to do this cheaper.
https://www.vevor.ca/aquarium-filtration-c_12592/vevor-aquarium-filter-317gph-4-stage-canister-filter-100-gallon-ultra-quiet-internal-aquarium-filter-with-uv-protection-submersible-power-filter-with-multiple-function-for-fish-tanks-12w-p_010163871331
4 stage 317gph.jpg

id pretty much saw the process coming in being pushed through then being pumped out. for a complete reset of the system the 3 stage RO would come in.
 
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Why do you want to clean it? Hydrogen peroxide not enough?
Hydrogen peroxide works great for handling pathogens and algae, but it doesn’t take care of salts, metals, and other materials that make wastewater dangerous for the environment (like eutrophication). Do I need to do this project? Absolutely not. I could easily keep dumping 1-10 gallons of water at each reservoir change. But I love learning new things and enjoy DIY projects, so why not take on something relatively complex and educational? to say i can and feel that fulfilment of completing it. I'm still on cloud 9 after the successful creation of my RDWC.

Of course, there are plenty of willful oversights on my part, like what to do with the filter waste. Have I just created a new problem by needing to discard those safely? Is it really worth it? Probably not. But learning how is worth it to me.

There are other reasons, too: with this project, I could apply for grants at school, and with urban growing being so popular at the college, it would fit right in. Plus, it gives me a chance to chat with others and see what everyone else is thinking.

cheers.
 

MidnightSun72

Well-Known Member
Apologies, long weekend up here in the great white north. This is such an interesting idea, I would never have thought of using a centrifuge to filter.

got some concerns that ill need to read up on:
1. moving parts: there is a lot of force that goes into spinning those fast enough to make it useful. I'm worried about wear and tear/replacement part costs.
2.overall cost of a centrifuge: i know its beyond my skills to make my own centrifuge, so ill have to buy one. what size, RPM, would i need to make this worthwhile and cost effective.

ill post when i come up with number and items but I'm not even sure what data i need to find to be able to calculate this...im going to whiteboard this when i get home from work and see what i can come up with.

thank again for this I'm going to at the very least understand centrifuges after this.
I don't think a centrifuge can clean the water to the degree you are looking for though I find the idea really cool.

We use centrifuges at work to clean water for tunnel operations. But we have to add chemicals to the water which helps solids floculate and then be seperated by spinning. Essentially a bigger heavier molecule will bind to the impurities you are trying to remove by increasing their mass you can then spin them out to the edges and separate them from your clean water.
 

amneziaHaze

Well-Known Member
Hydrogen peroxide works great for handling pathogens and algae, but it doesn’t take care of salts, metals, and other materials that make wastewater dangerous for the environment (like eutrophication). Do I need to do this project? Absolutely not. I could easily keep dumping 1-10 gallons of water at each reservoir change. But I love learning new things and enjoy DIY projects, so why not take on something relatively complex and educational? to say i can and feel that fulfilment of completing it. I'm still on cloud 9 after the successful creation of my RDWC.

Of course, there are plenty of willful oversights on my part, like what to do with the filter waste. Have I just created a new problem by needing to discard those safely? Is it really worth it? Probably not. But learning how is worth it to me.

There are other reasons, too: with this project, I could apply for grants at school, and with urban growing being so popular at the college, it would fit right in. Plus, it gives me a chance to chat with others and see what everyone else is thinking.

cheers.
Interesting idea but tell me what do you do with the full filter? Do you maybe dump it aswell?
 
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