I have a 110g tank with 6 t5ho's 54w and co2 w/controller and reactor,uv light,eheim 2028. I had just redid my tank with soil master select for my substrate 3 months ago and cycle went ok , Now i have been fighting BGA , my PH is 6.7 and the end of each week i have to add baking soda to keep my KH at 4.0, I have tested my KNO3 at 0 so i add some to raise it to 5.-10. my PO4 reads at 3. witch i did not add any at all , I did replace 2 t5 for some 10K {my t5 are over a year old ad i would like to get 1 more 10K and 3 6700K}. Does it take some time before these nutrients do get absorb into the substrate or am i doing this all wrong, I don't have a lot of plants to began with and i do need to get a lot more in, Can i just throw in some floating plants to get by, What kind of readings should i have and do i need to add anything else, I have been doing water changes every week to keep the BGA down!! need help