Uneducated grower/single plant. - small quick mystery, please help ASAP.

Hi, firstly I'm growing an automatic northern lights marijuana plant from spanish seeds, it is just for an experiment and i don't want a brilliant harvest since I'm aware I don't know much about it. I have grown one plant in past in the sun before and got a small harvest which i was content with but this grow i'm doing right now i would say is actually more advanced than my last one due to the greenhouse and lights etc. So here goes:

I started off growing it under a 23w cool white CFL light along with a 20w warm white CFL light which i know is not ideal however i did have them close to the plant. It was going well till the very few leaves my plant did have started to go dark green, sort of hard and easy to snap and a quarter of the leaf was light brown.

Despite the weather not being great, i bought a small plastic greenhouse which got the plant to survive and grow new leaves. So it is still growing good leaves when i have it in the greenhouse and then i bring it in the CFL's at night.

I am growing in standard soil which i believe not to be pre-fertilised it is just called 'potting compost' but i have started feeding my plant baby bio since it has started to grow good leaves from the greenhouse

HOWEVER, here is my problem , the leaves are canoeing but downwards and they are sort of curling round which are shown in the pictures.

ALSO, i have these tiny white flies under my leaves which i believe to be aphids because i have basil and other things in the greenhouse which perhaps attracted the flies. These pictures are taken in the CFL area since the sun isn't out.

Hard to say but probably an issue with your compost medium or nutes. If it isn't your own compost it can be difficult to know exactly what you have. Always a risk that it wasn't fully composted and may be hot. It will retain a shitload of water so getting good O2 exchange can be an issue because you don't water it as much. Who knows if it has all the micronutrients needed. So a lot of unknowns about your medium and we also don't know what level of nutes you have been feeding or frequency.

Your newer growth looks better, is that what you are seeing? If so it may be okay growing through whatever was off earlier in the grow.

Okay thanks