i did consider using hg myself, as its obviously limescale that blocked my filter, my fault for not using a water softener and back washing everyday with salt.
however i went out and bought two membranes as i fear the damage is too great im too late.
after some reserach i see i could also have improved my back wash techniques, i never tested the output of the backwash i should have checked the backwash until i get the same ppm as tap water.
Also now hears the big reason i never tried hg! well i know it will react very viciously with metals it will bubble so much it will tear your membrane to pieces, however there is a solution you can use , SALT!!
you can backwash with salt using your high pressure pump, membranes remove salt salt will loosen the metals, i dont expect it will fix a blocked filter but improve it and service it prevent it getting blocked.
A 30 second blast of Salty solution is the proper way to backflush then backwash
Im also adding a 25lt can of acid washed carbon granulated media as cartridges are no way up to the job, i then be checking the ph and nitrate levels is ok lol
May god forgive me if i put extra salt briney solution in my 4040s and deliver me pure water for eternity
as for the poor guy who got roasted using caustic bloody soda my god did you mean to use soda crystals cos they wood be ace i bet but still very strong stuff, soda kills algae nicely too
caustic soda is bloody dangerous it boils up instantly , dropped on the floor it will eat through the floorboards etc put it on you it will eat right through you, its the strongest alkali so you probably need acid vinegar to neutralise it. if you ever need to unblock a drain it will save you digging up the pipes but never play with it empty it all out and run never leave it in your house
i swear my water rejection rate is different now my soft water flows lovely i have two 4040s and only need one, i got it all on a converted ionics trolley on a skid inside my land rover with only a small holding tank, i dont want to carry too much weight ever i buried a cousin this year from his lorry accident i dont want to be next. i have a honda silent generator for the boost! the line of filters is growing and i have about 6 extra tubes to fill if i can get any more water pressure i will add more filter medias