Why is plant growth slow?

Remember please take advice from experienced growers in your substrate type. Grannie,, no offense, but you do not know anything about coco grows. I have been doing them for years.

Okay so after looking at your diary. You are in coco. So first you are not watering right. I can see in picture. Coco Is Hydro growing. I grow in coco every day. Ph is extremely important in coco. So you need to soak the whole potter with 5 8 ph water and then measure ph run off. Should be 5.8 in 5.8 out in vegging. 6.1 or 6 .2 in flowering. Anything below or above this range is lock out. You can not grow in coco like you do soil. Again it is Hydro in a potter. It thrives on heavy irrigation. Never let it sit in run off. Always keep wet. Watch ph like a hawk. Always provide nutrition after a good ph flush to refresh coco. You will also need a cal mag growing in coco. Can do me for more help.