Bio-Load and Temp Controller

I have two questions:

1. Bio-Load. I am very familiar with the nitrogen cycle and i have read the post about bio-load. My questions is doesn't bio-load at the end of the day translate directly to nitrates?

2. I have 75gal with two Hydor heaters inline on two separate canister filters. I am looking for a temp controller. I would like something with WIFI and alarm for both heaters. It looks like it can only find either a controller that will work both heaters and not alarm, or WIFI with one heater and one chiller. I have been looking at inkbird. What does everyone use or does anyone have suggestions?

I've never used temp . Controllers sorry and the bioload IMO can be indeed translated as an amount of ammonia- nitrates production per gallon of water .
Fish farms if i recall correctly , prefers to measure weight of fish per gallon of water to estimate filtration and water capacity needs . Basically the same thing .

Temp. Controlers Higher recommend! I keep mine at 29C with a 1 degree var. Less fluctuation then F. I have set it at 28.8 on 4 of my 29 gal tank and my age barrel and it is dead on every time . I have grow outs now so making it high now.