I've never used it in my water but I absolutely love Oxine for sanitizing surfaces. So much less offensive than bleach. They also market to hydroponics I've seen. From their website below.
"Oxine (Chlorine Dioxide)
Oxine is a multipurpose liquid disinfectant which is many times more powerful in eliminating micro organisms than common chlorine based materials or
hydrogen peroxide.
The beauty of this product is that it is a very powerful oxidiser yet it leaves no harmful by-products behind.
When Oxine (a patented stabilised Sodium Chlorite solution) is activated with citric acid it forms a stock solution liquid which emits Chlorine Dioxide gas (ClO2) – a very powerful Oxidising agent.
(Chlorine Dioxide (ClO2) derived from Oxine is not to be confused in any way with swimming pool Chlorine, or industrial strength applications of low grade ClO2 – they are totally different)
This ClO2 stock solution is then added to the body of water requiring treatment. The ClO2 immediately takes action and begins oxidising any harmful micro organisms it comes in contact with.
It is the Oxygen in the molecule ClO2 that is so active. After the oxidation of microorganisms takes place the Chlorine (Cl) in the ClO2 molecule finishes up being combined with Sodium (Na) to form a harmless degradation product – common salt (NaCl).
It is the powerful oxidation properties of the ClO2 molecule and the harmless by-product it leaves behind (common salt) plus its gentle action around living plant tissue which makes Oxine an excellent product for hydroponics.
The common salt left behind as a by-product of the oxidation process is of low toxicity and can easily be monitored and removed from the system should they ever built up to unwanted levels. In hydroponic systems these levels are usually negligible provided there is not an elevated content of sodium already present int he water supply. .
Oxine overcomes the shortcomings of all other Chlorine based products which allow troublesome organochlorines to form when chlorine reacts with organic material.
The Oxine product is unique in that the patented method of manufacture and stabilisation produces a product ideally suited for use in horticulture.
There are other low grade industrial ClO2 products, used in industry, that have caused problems to plants and these products are not to be confused with Oxine and Oxine should always be asked for by name.
The Oxine application rates for hydroponics are as follows:
2ppm – The standard dose rate for fully sanitising water supplies used for hydroponic systems or human consumption. Can be directly added to a tank or dam or injected inline via a proportional injector. Targets Pythium, Phytophthora and similar water borne pathogens.
2ppm – The standard dose rate for adding to nutrient solutions fed to crops. The 2ppm strength targets pathogens and other harmful microorganisms, controls algae and unblocks drippers while being soft on plant roots and plant tissue. The recirculated residual helps to keep NFT gullies clean and free of organic loading. It has been successfully used for cleaning up fungal infections on root systems.
5ppm – The standard dose rate for adding to nutrient solutions which are fed to plants in run to waste (non recirculating systems) when fungal problems are present in the media.
10ppm – For the control of bacterial soft rot on Calla foliage/tubers to prevent spread within the crop. Used as a foliar spray. Not compatible with copper sprays which may already be present on the foliage.
50ppm – For flushing through drippers, drip tape and other pipework to sterilise them between crops or when disease problems occur. Great for removing biofilm from pipes, gullies and drip systems. (Plants must be disconnected from the gullies or drippers and pipework must be well flushed with fresh water before reconnecting to the crop). When used with a wetter/spreader the level of contact and effectiveness increases.
50ppm – For flushing through reusable media to sterilise it before it is used for the next crop e.g coconut coir, pumice, scoria
100ppm – For disinfecting processing lines, greenhouse floors or harvesting equipment. As a soak bath additive to sterilise growpots and propagation trays and other equipment. Will loosen stubborn organic matter and biofilm. No rinsing required after application. Can also be applied as a fine mist. Ensure surfaces are wet for at least 1 minute.
Contact Pure Hydroponics for more information and pricing on this world class multipurpose disinfection product. "