When using LEDs, what constitutes "high light"?

This is a good starting point to reference.

http://www.plantedtank.net/forums/10-lighting/184368-lighting-aquarium-par-instead-watts.html#/topics/184368

 

Manufacturer claims about performance are probably sugar coated

Rotalabutterfly.com Has a light calculator

Tropica.com has some detailed information about individual plants

I have read here many times that low to medium light, and good co2 is the way to go. When you step up to high Par and push the envelope theres a better chance to crash.

 

I started out with a 40 breeder running a Current USA Satellite+ -- this was before they introduced the +Pro. I believe their PAR claims, I suspect I was getting about 30 umol at the substrate. It worked well for the staurogyne, mosses, and java ferns I was growing at the time. I tend to think that a manufacturer would be dumb to do anything other than report actual measured values from a sampling of their products.

I wouldn't necessarily trust the light calculator, the assumptions it is based on seem like a stretch at best. So many things (components, reflectors, ballasts/LED drivers, etc) affect the lighting efficiency of a system for the amount of power put in, it's a REALLY difficult thing to model compellingly.

Ultimately, I think the light you've chosen will work well for anything you'd want to grow -- don't overthink it! The most typical assumption we see around here is

"I want to grow plants, so I need ALL of the light! ALL OF IT!!"

I bet you'll do best running that Satellite +Pro at 60-70% for starters. There are relatively few plants that require more than that.

 

Hi....I'm not anywhere near expert level, but I think it makes sense to have the par level for high light at a lower level because high medium light without CO2 can be really problematic. According to Tom Barr, many nature-style tanks have around 50 micromoles of PAR at the substrate, yet they can still grow "high light" plants.

 

Yeah, a majority of the newcomers I see here and elsewhere want crazy high light, thinking it will make their plants grow better. Your better bet is to have just enough light to get your plants to grow the way they are naturally supposed to. A great majority of plants will get by with 50 PAR or so, and more than that is just going to drive algae. When you are more familiar with the various aspects of your tank, you can start to increase light to get some of the more dramatic tanks you see on this forum.