TDS meter and lighting question

[Funky_Fish14]

How big is the tank? No, I wouldnt say thats too much light. I have 2x 400W over my 75 gallon reef... everything is happy. Its only 20" Deep, and the lights are 12" above the tank - Single ended, sometimes I run with glass lids for evap, and sometimes not.

And the TDS in your topoff water depends... Right out of my R/O Membranes (in the new house we are moving to) i get 42ppm TDS, but im starting with 850ppm TDS... What kind of prefilters do you have? Do you use deionization resin? And what kind of water are you starting with? This will all affect how 'good' 53ppm TDS is on your output water, and the frequency at which you need to replace your membranes.

Cheers,

Chris