Is everything ok?

Hey m8! I checked your diary aswell, so basically its normal to have slow growth at the start but indeed they should grow much faster. -> I see in your diary your lights are 600w at 60cm, I assume they are dimmed? Otherwise they may be getting too much light. -> 20 degrees day time temp is rather cold, it shouldn't be much of a problem but you will have faster growth rates at 24-28c (remember to dose your nutrients according to temp, the higher the temp the more the plants transpire so the more diluted their water reservoir needs to be) -> slow growth with everything above ground seeming 'ok' usually hints towards a root problem, since they are seedlings the roots are sensitive at this stage. Are the roots aerated enough or does the grow medium seem very compact? I have never grown in coco before but I think you can add perlite to aerate it more (but search a guide on google 😎). In soil this quickly happens when the soil is not very aerated and when watering too often. Feed at approx 1/4 strength nutrients at this stage, nutrients should not be an issue, they need a small amount and its better to not give enough and adjust when you see they are hungry than it is to give too much. I hope this help, good luck m8 👊