I'm growing this plant very carefully to not ...

Hi @BadKarma! Nice Indica you got there! With only 45W of LED lighting buds may take longer than breeder's schedule to really fatten up and express their potential. Especially if you're not using a bloom stimulator and keep feeding with Nitrogen (alga-grow). Now that you have passed the 4th week of flowering, plant should have ended to stretch and should be focusing its energy onto buds production. Nitrogen is no more necessary and might lead to overfeeding symptoms. All she needs for now is a good P+K booster to properly develop the bud sites and expand its calyxes. Do you have some Alga-bloom in stock? Or any other blooming stimulator that contains enough P+K? Finally, your night temp is the lowest temp cannabis can usually handle with no issue, so if possible you should try to raise your night temp to 18-20°C, this should help her out. It is also true for your daily temp, 18°C is a bit low, try to push to 23-25°C for best results. Finally, checking and adjusting the pH and EC of your feedings will dramatically help her to grow big & sticky buds. If you don't have the appropriate testers, you can find them at your local growshop for a few dollars, ask the reseller to calibrate them for you and to show your how it works. Hope this will help, keep us up-to-date so we can help you to refine the parameters, and happy growing