Hey, thanks for the welcome. If they let out heat they are going to cause more harm than good I recon. Could be an option over winter though.
I will get some leds priced up, even if they are expensive I suppose I only have to buy them once and the use I get from they will pay for themselves over time, as I no longer have to buy weed.
One of the plants is a darker green than the others could this be down to lighting and it wilts a lot, then some days it looks like the healthiest plant going. Could it be bacause I can't get my soil to shift from ph 7.8?