uv sterilizers

[ericst11]

i use a 12 gallon reservoir and pump my water out 1in hoseing to water my plants has any one use a uv sterilizer to clean there water or know if they really work . thanks

[Ray]

Yes, they work. Used one on a marine aquarium for years.

I doubt there's much need for it when watering plants.

[ericst11]

how about if your water reserculated back into the reserve.

[Royal]

UV is used for disinfection in water treatment. If it can handle poop water, it can handle orchid water.

[Ray]

Originally Posted by ericst11

how about if your water reserculated back into the reserve.

You don't do that! (That's actually one of the features of "semi"-hydroponics.)

Yes, the UV would likely kill plant pathogens, but it does nothing to the chemistry of the solution, and we're intentionally trying NOT to reuse that.

[ericst11]

how about if your growing your plant hydroponicly not semi hydroponicly.

[Royal]

I think it would work well. As I said, it is commonly used in the water treatment field, and other applications like large aquariums. The main drawbacks are the cost of the bulbs, and how turbidity reduces efficiency. Bulbs will need regular cleaning, and really dirty water inhibits light penetration. For clear-ish water (like aquariums) it should work like a charm.

[Ray]

I guess that if you got nutrients with no dye in them, and significantly oversized the sterilizer to ensure penetration, and passed 100% of the solution through it, it might help somewhat. (In aquariums, typically only a portion of the water passes through them at one time, and its the constant recirculation that keeps the pathogen population at-bay, but never eliminated).

I still don't like the idea of plants sharing a nutrient bath, though. Picture adding a contaminated plant to an otherwise "clean" collection. The solution bath is an ideal vector for the other plants to get contaminated, and the UV only kills those in the water passing through the sterilizer, and has no impact on that in-between the plants. It also will do nothing to kill pathogens within a plant.

[ericst11]

so you don't think that the uv sterilizer would kill disease and fungus in the reserve. when the reserve is on a timer so it has time to clean between waterings.

[Ray]

The UV will only kill whatever is exposed to it. If the nutrient solution storage tank is still and the UV is sufficient to penetrate all the way through the liquid, it will be reasonably-well purified. If, on the other hand, you pump it through a sterilizer - the standard kind with the bulb in the quartz tube surrounded by the water tube, for example - you will kill a percentage of what passes, but then dump it back into the still contaminated bath. Think in terms of a radioactive half-life -- you kill some with each pass, and the pathogen concentration gets lowered, but you never actually kill everything.

Keep in mind that such a scenario:

1. disregards the possible replenishment of the pathogens in the solution outside of the sterilizer,
2. does nothing to kill those residing in the plants and medium (which will "recharge" the solution at every watering),
3. the more frequently you pump and water the plants, the more contaminated the solution becomes,
4. while you are in the watering mode, plant-to-plant pathogen transfer can easily happen, and
5. if one plant succumbs to something, every one sharing that nutrient bath now has to be treated.

Don't get me wrong, I'd bet that with sufficient sterilization capacity and careful selection of "disease-free" plants added to the system, you could probably have a quite successful operation. I'd just bet it will be quite expensive and hard to maintain "clean".