Best thing for a sterile reservoir is bleach. Start with 1mL (per 10 liters of reservoir water) of regular 6% household bleach.
Gotta keep that reservoir cool at all costs. You may be able to kill the fungus with fungicide but it’ll keep coming back and there’s less oxygen available at warmer temperatures. Bleach is still very helpful though for proper reservoir maintenance.
Using calcium hypochlorite, adding enough daily to raise chlorine levels 1ppm.
Keeping an eye on it with an ORP meter, somewhat non direct number but does give an overall indication.
Just got pool test strips for free/total chlorine but alas, doesn’t show much, hovering on the lowest readings. Dont feel comfortable whacking in enough to get 1-2ppm free chlorine, not yet at least.
You can go way higher than 1-2ppm. Try 5ppm. Besides, it evaporates so quickly.
Wont oxidize all the iron out of the res?
Have done shock treats in the past, first time with long term use.
Did build a chiller, thermostat keeps it 19.5-21C. Had it at 18-19C, but the power usage is just silly, 250-300W (peltier) 50% active time, my LED only draws maybe 150W.
I haven’t found this to be the case.
I did find an interesting paper that says while sodium hypochlorite will inactivate EDTA (assuming you use iron EDTA), it needs far higher concentrations than we would ever use to have a significant effect. They were using 1% (10,000ppm) solutions, not 5ppm solutions haha.
Fantastic , will bump it up immediately.
GH flora does have EDTA, but 10.000ppm, no worries then 
Yes thats the stuff