Do I strip it all down and start again

HI
I have been battling a BGA problem for about six months I have tried more and more No3 + k etc . blackouts etc etc
this tank has been set up for about 4 years and was going great (photos of tank then http://www.users.bigpond.com/dmwilliams/photo.htm ) until we had a water shortage 12 months ago (Water from tap was unusable 650ppm in hardness could not even use it on the garden as it would kill anything it touched )
so I was using RO and adding all of the rest of the minerals etc.
then six months ago the BBA started and I beat that but then the BGA started and it has been down hill form there.
so my question is do I need to start all over again ,
Now tank specs
500 litres all glass no lids
280watts of Fluro lighting (10 to 12 hours)
pressure co2 through a 2000l / hour reactor
two 1200l / hour canister filters
Kh 130ppm
PH 6.8
No3 25ppm

Weekly 50 % water changes
add KNo3 (5g twice a day) otherwise the reading is 0 and the BGA is extreme
add K2so4 every third day 10g
add Mgso4 every third day 5g
iron and trace on water change

I am back to using tap water aged for two weeks in a plastic tank the tap water is 110 ppm Kh with a PH of 7.6

Thanking you for any assistance
outbackdean

 

Re: Do I strip it all down and start again

Hi Bill
Yes I am from Broken Hill as far as you can go west in NSW.
Gh is 140ppm
I have lost my B/nose cats and about 4 Discus That leaves four discus twenty odd cory cats
discus are feed a beef hart mix changing with blood worms four times a day.
BGA is mainly on the plants and the glass filter pipes etc.

Thanking you
outbackdean