It calculates that you have about 20 Watts per square foot. Not nearly enough. I assume these are T-8s, which put out about 80 lumens per Watt. You need about 50 Watts per square foot for leafy greens to do well.

The 6500 lumens and 40 Watts X 2 bulbs looks like what you have, although most 48" T-8s are 35 Watts. They are good for leafy greens and should be only a few inches above the plants; but as with all fluorescents, they do not concentrate their light so it can be directed over a distance, which is required in order to grow taller plants, such as those that flower. Go with the highest temperature of bulb you can get, not the highest lumen rating. Lumens are measured at 550 nm, which is green. Not a very usable color to grow plants. Higher temperature bulbs will have more blue, which is what you need for leafy greens.

As to the LED grow lights, most are designed for the cannabis business, which is flowering plant and in need of lots of red light. Not very good for leafy greens; but if you have enough wattage and the proper lenses on the bulbs, they will work well for your flowering plants, once your system is mature enough to grow them.

In order to get enough DLI (Daily Light Integral, the total light needed in a 24 hour period) for leafy greens, you will need about 50 Watts per square foot for at least 8 hours per day. If your light is less than this, then you will see the plants growing long legs trying to reach for the light that isn't there. Much less than this and they may not do well at all.

With your Nitrates where they are, if you have properly sized your grow beds to your fish tank and your fish are small, it is best not to plant very much in your grow bed until your fish grow out some. Your Nitrate levels will tell you if you have the right amount of veggies in the system. Think of the fish as being full grown and grow bed(s) full of veggies and now scale back those plants to amount of fish size you currently have in your tank.

Oliver