uv sterilizers

[Royal]

I agree with Ray. UV light will, in theory, disinfect well. But,as a complete system for sterilizing your fertigation -- I wouldn't advise it. It's not just as simple as hooking up your lamp and passing some water over it. There are many factors to consider, as Ray stated.

UV irradiation IS typically used to inactivate waterborne pathogens such as bacteria, viruses, protazoa, and fungi. UV irradiation is used alone (photolysis) to remove total organic carbon, and is sometimes used to remove chemical disinfectants such as chlorine, chloramines, and ozone from water. Advanced oxidation processes must combine UV irradiation with chemical oxidants (like hydrogen peroxide and ozone), or with semiconductors (such as titanium dioxide) to oxidize refractory chemicals including chlorinated solvents, taste and odor compounds, NDMA, MTBE, pharmaceuticals, and endocrine disruptors. UV is able to alter the chemistry of a solution, but only in conjunction with other oxidants.

It is possible to completely sterilize and reuse this water safely, but at what cost? What is the point to begin with? It would be soooo much easier to just use clean water, and probably economically and environmentally more responsible.

12 gallons of water vs. electrical costs, mercury-containing bulb replacement, maintenance, safety, and worst of all - risking the health of your beloved orchids. Sounds like way to much risk and hassle when 12 gallons of water is only a few cents. Just my .

[ericst11]

thank you guys for your input and i just went with two tubes one that i pump water onto the plants with a home made watering wond and another that catches the waste water and is gravity drained into the house main drain and some times i use it to fertilizes my out door plants. so it's not a total waste thanks.

[Gold3nku5h]

This is kinda off subject but with regards to the UV.* I am going to setup a paludarium in the near future (half land, half water).* It will have a waterfall, stream, and shallow pond, where it drains through the media into a reservoir.* After that it will go through a pump and line, back into the waterfall.* If i place a UV bulb running a distance along the exiting line of the reservoir, will that be sufficient to kill off any unwanted bacteria?* Should i not worry about anything harmfull to plants, or animals (it will eventually have poison dart frogs).* Also the reservoir will maybe have another setup for additional plants to clean the water.* MAINLY what exactly does the UV kill off? Also what would the things (that would die) do if left in there?

[Ray]

Forget worrying about the plants, UV is not particularly good for you!

UV bulbs used for actinic purposes in reef tanks and the like are not effective at killing microorganisms, as the glass that is used to make up the bulb blocks/absorbs the effective wavelengths. The UV sterilizers typically consist of a pure quartz (SiO2) bulb surrounded by another quartz tube, all inside of an opaque housing.

Quartz glass does not absorb any of the UV rays, so the water passed between the outer wall and the quartz tube surrounding the bulb are exposed to the rays, while the world around it is not.

The carcasses of whatever is killed, being organic matter, will decompose. We're talking mighty small critters, so you'll never know they're even there.

[Gold3nku5h]

so i can be completely fine without it? Does it kill off possible disease and unwanted mold and fungi?

[Ray]

If your environment fosters the growth of such pathogens, sterilizing the recirculating water will be of little help.

[Gold3nku5h]

ok, thanks. but just to get to know why... Is that because it will kill off things that wont really harm the plants or animals? Or because it will be recirculating what is not killed, and will be able to freely multiply?

[Ray]

If you have an environment that favors the growth of molds and other fungi - too cool, too humid/wet, insufficient air circulation being a terrible combination - your plants will suffer no matter what else you do. The UV will be irrelevant.

Think first about the needs of the plants, set up the environment to accommodate those factors, and you should have no difficulties with plant pathogens. If you want to add the UV to treat the recirculating "stream", it won't hurt anything, but probably won't be a big help, either.

[Gold3nku5h]

yeah, i guess thats true.* I've never read any situations where people building any kind of terrarium needed to use UV sterilization with living plants in the system..* It just concerned me when it was mentioned here.* Thanks for the info, and on your site.