I want to know what could happen with Fastberry an...

Yes temperature plays a big role in plant growth and delevlopment. Firstly your day/night temperature differences need to be midigated and controlled. If at all possible the day temperature should be brought down to mid 70’s. Secondly at a 7 ph some of the nutrients are going to be locked out. I would recommend a slightly acidic watering and feedings at 6.5. This can better assist the access of nutrients to your plant. Hope this helps, good lick on your grow!

Hi @Diegodelmar! Indeed, FastBud's strains are not supposed to be so slow. I don't think your day temperature is an issue, as 28°C seems fine and I grew many FB's strains under this temp, but your nights are a bit cold and the difference is huge (-11°C), such temperature fluctuations can lead to bad photosynthesis. I suppose they're looking really sad in the morning when your light turns on? If so, issue is confirmed, night temperature should be fixed. Now about waterings, your soil looks very wet on the pictures, do you let it dry between each waterings? It needs to be on a dry/wet cycle, in order for the roots not to suffocate/get drawn and to keep on spreading, searching for water. As you guessed, those two issues are slowing down your plant's growth and will potentially impact your final yield if nothing is done asap. As an emergency move, I would let the soil dry for a few days (feed with foliar spray if needed), and do everything to raise up the night temperature by 4-5 degrees. One way would be to put your plant on a 24/24 schedule, with the light always ON. FB's strains are known to work pretty well in a 24/24 schedule. Another way would be to turn the the light on after the sunset, but this might reverse the issue (with too-hot nights for your plants). Hope this helps, I'll be around, keep us up-to-date and happy growing!

Yes and yes. Low temperatures at the very least will slow growth down to a crawl or stop it altogether. For good results, temperatures should be kept above 23°C (73°F) for good vigorous growth. If your ambient temperatures are too cold, try to lower your fan speed or put it on a timer (15 min on / 15 min off). For that small a plant 250 cc of water is too much; try with 250 cc for 4 or 5 days and only water if the soil is dry, if it dries in 2 days, up the amount to double that (500 cc).