well then. I may try to transition the system from using primarily floating plants to vine type terrestrial plants and algae to control the nutrients. any tips to help provide lots of surface for the algae to grow on and be easy to harvest? perhaps try using the material often suggested for saltwater diy algae scrubbers?
As for the UV I was just looking into getting one that is massively overkill for the size tank. 36 watts stainless steel. I was also planning on a fairly low flow rate to try and give myself as good a chance as possible to break down the growth hormones if it is even possible with a UV sterilizer. Can any negatives be expected putting a sterilizer meant for a 4000 gallon pond on a 40 gallon tank with a sump?