I would try without the ferts, my setup is similar to yours - just less than 2WPG with pressurised CO2, Aquabasis and hard water. All of my plants grow really well and I'm trimming, chopping and throwing away tonnes of plants each week. I have some JBL Pro Flora and have tried it a couple of times to see what would happen, but it's made no difference. I'm sure if there was more light, then I would need to add more ferts but at this light level they do exceptionally well with just the traces in the tap water.
Saves you money too !!