It was recommended 75g for 3 gal , so figure safe around there and you can always add in for deficiency. I personally run on the lighter side so I can add in my own boosters.

4 gal is the same size I use. What’s in your pro mix medium? I grow in straight coco coir, also in buckets. For coco coir with nothing else, I added 5 of the 75 gram bags, so 375 grams in total into 24 gallons of coco. That put me at 62.5 grams of Grow Dots per 4 gallon bucket, of which I currently have 6.

Again though, I don’t know anything about the medium you’re growing in. If it’s more than just a substrate that holds the roots and gives them access to the water at the bottom and the nutrients in the coco with them, you will need to adjust. I would suggest @one-eyed-cat or @jmystro as they will know more for sure. One or the other has basically fixed every problem I’ve had so far. 😂👍🖖💪💖

With unknown seeds, go with estimated flowering time to get an idea of how much it’ll need. Longer flower time I’d go with 100 grams in 4 gallon. If flowering time is short, then I’d go with about 80 grams in a 4 gallon.