So Ive been dealing with the slime for months and thought my hydro days were over. I'm now in full recovery and want to share what helped fix the issue. The knowledge I gained on the subject through the forums was priceless, so I want to give back.
First of all, the first thing people say when someone is having root issues is to keep nutrient temperatures cooler. This does play a part and I make sure my reservoirs never go above 72F, but I personally feel that keeping a lower PH helps even more. Studies show that root rot is killed at a PH of 5 or less. Also cyanobacteria is rare at a PH under 5.5, and completely nonexistent in a PH below 5.0. Now that I let my PH drift from 5.0 - 5.5 I have had much better growth. Ive even had my PH get as low as 4.6 for days and saw no negative reactions in the plants. Btw I have an oakton double junction ph tester that I calibrate weekly.
Second of all, Ive found that using Z7 enzymes really helped me recover from slime. It also works very well to keep roots healthy while the plants are still young and vulnerable. Its better if used as a preventative, but can definitely help reverse a problem if you clean out your system, rinse the media and roots in water, and prepare a fresh reservoir with Z7 added last. If you are desperate to save a prized mother or some vegetative plants you can add ridomil to reservoir 24 hours before a change out at 1ml per 10 gallons. Only use ridomil as a last resort, and never on flowering plants.
When cleaning equipment I recommend using the blue Clorox non-bleach spray. It is the same exact ingredients of Physan 20 in a convenient spray, located at any local store. Don't use it on filters or air stones though because its hard to rinse out... only use on hard surfaces. If you had a grow with hydroton that got infected, do not reuse hydroton without rinsing in water and then boiling for 15-30 minutes. You can get a 5 gallon pot at Wallyworld and boil it on your stove. For dirty fittings, let them soak in rubbing alcohol and use a wire brush from homedepot paint section to clean the insides. For hoses, use a long tube brush, mine is about 3 ft. You should clean every component of your system after every use to the point that everything looks brand new again.
Now on to the other factors. Never bring soil plants near your hydro plants. If you accidentally get a little soil in your hydro system it can be HUGE problems and contamination of bad bacteria. Next, make sure you keep your room, house, and yard as bug free as possible. If one of your plants is infected with anything, the bugs will spread it to other plants even if they are in separate systems. If you have an infected plant either throw it away or isolate it, or it will spread. Do not use neem spray or azamax. Neem spray is antibacterial and antifungal and works systemically affecting the whole plant and throws off your beneficial bacteria. Azamax in the reservoir can lead to blocked up lines and slower flow rates. Instead use spinosad spray and microbe lift in the reservoir. Also, keeping co2 levels 800-1200 ppm deters a lot of bugs, and gives plants a growth boost making them more able to fight pests/disease. I recommend using silica in hydroponics (I use protekt 4ml/gal) because silica make leaves/stem stronger and more resistant to pests and disease. It has also been shown in studies of food crops that 100 PPM Silica in the nutrient solution protects roots from rot. Make sure to use at least .5 watts of air pump per gallon, and a beneficial bacteria in your nutrients (I like hydroguard).
Some people may not agree with my recommendations and that's ok, I just wanted to share my experience and possibly help others because this slime can be extremely painful and frustrating to deal with.
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