The first forum I joined last year I ran accross a thread where a guy is using unsweetened lemonaid (koolaid brand)and says he's getting great results.He said he uses 14 packs to a gallon of distilled water(he also said don't add the sugar),gets great cell production and said his plates remain almost spotless.
After taking my tero cell apart last week after several month's of use to replace the spacer gaskets with thinner ones,I found that my plates had a dark brown almost black film on most except the end plates.Some of it could be wiped off,but most of the stains are embedded into the 316L plates.My tero cell runs very cool about 115deg.F so I know it's not from excessive heat,even though it draws about 35 amps.After painfully resanding and reconditioning the plates(8-9"x9") I've decided to give it a whirl and try the koolaid over the KOH I've used in all my cells.
Citric acid is in fact an electrolyte and should do the job,I just don't know if my gas production will be the same,but if I have to lose a little gas and not to have to deal with badly stained plates again it'll be worth it.
Should have everthing back together this week and I'll post results as I get them.