Pythium - the evil fungus and what to do about it.

Well after much research it has been concluded that Pythium was the cause of my strawberry failure.  The factors that lead to this outbreak were:

• High nutrient water temperature.  I set up my system in the fall thinking that temps would start to decline, unfortunately shortly after planting the strawberries we had record high temperatures.  The nutrient water climbed into the high 70's.  Read More

• Transplanting established plants from soil. I did rinse most of the soil off, but I wasn't aware of the dangers of taking a plant from soil straight to the hydro system.  It is imperative that if you must use plants that were in soil, that you thoroughly clean the plant from ANY organic debris.  It is preferable that the plant is quarantined in fresh water and continually rinsed to make sure that all material is off.  Then soak the roots in a weak (the kind you buy in the store) Hydrogen Peroxide solution.  This will get rid of any remaining organic matter and remove any damaged parts of the plant. Read more

• Make sure the plants aren't stressed.  In my case I was overwatering the strawberries and stressed them in that way.  Stressed plants will succumb to pathogens more readily than healthy plants.  Make sure that the growing conditions are correct for the type of plant you are trying to grow. 

• Sterilize the nutrient water OR grow beneficial organisms.
• Beneficial Organisms.  There is a lot of conflicting research out there about how beneficial "good" bacteria and fungus are for hydroponic systems.  Some say they help increase the amount of nutrients a plant can uptake and fight off pathogens.  Others say that the nutrient water is already full of nutrients in plant friendly forms so there is no need for these organisms that are useful in soil horticulture.  I vote it can't hurt, even if the plant isn't getting any additional nutrient benefit from the microorganisms the protection granted could be worth it.  
• Sterilization of the nutrient water. There are two common ways to sterilize your nutrient water:
• UV.  There are a variety of inline UV sanitation systems out there designed for aquariums as well as hydroponics.  They range in price from $50 to $500 and are fairly effective against killing off most micro organisms.  However, they may not destroy all spores.  You can use UV with beneficial organisms, but must turn off the UV for a few days to allow the organisms to colonize the root systems of your plants.  Otherwise you will just kill them with the UV. 
• Ozone.  Ozone is the nuclear option.  It sterilizes the water, but if used incorrectly can cause health problems to the operator and damage the roots of plants.  You can not use beneficial bacteria or fungus with Ozone, it destroys everything the ozonated water touches. Also, ozone generators are costly.  This might be a good alternative in a large scale system, not great for the home hobbyist.

Basically, make sure your plants are healthy, monitor your plants everyday (TDS, pH, visual inspection of the roots and nutrient water) and most importantly, keep everything clean.  This is what I have learned thus far, hopefully round two will be more successful.