Can't stand this newbie issues

[NAS]

Check your source water for nitrates and phosphates.
Have a look at your water tone (look through a zip lock in day light yellow=doc's) DOCs can skew your spectrum.
Bulb Age?? Type?? Could be starting to slide. . .

Hammer the Phosphate and nitrate remover. . . An AT LEAST TOP OFF WITH RO.
If you get ro from a store (like i du cuz im lazy) then b sure to test it for phospates/nitrates. Some less the cool biz owners in the past have skimped on the RO and done RO/Tap cut at stores.

Most likley cause all tanks are effected at same time it's Source water/hardware.