So i have an iron block in my base and when i set the chunk loader to 3x3 it works fine no problem... but when i try to set it to 5x5 or anything bigger it says in the chat "You reached your chunk loader limit (9 available 25 needed)"
The chunkloader limit is based on the total amount of chunks you are loading. As a deafult player, not patron rank, you have a maximum of 9 chunks available for online loading. When you activate a 3x3 chunkloader, you are loading those nine chunks (3 times 3 is 9) and not just three. To load 25 chunks (the amount a 5x5 loader requires), you will need to be a paying patron member (you can read more about our patron ranks here: Patron - MineYourMind 5.0 ). As you do not have a patron rank, you can therefore not have an active 5x5 chunkloader. Seeing as I have answered your question, I will go ahead and mark this thread as done.
As a nonpatron, you're limited to how many chunks can be loaded at one time. For iron chunkloaders, 9 chunks is the max. Offline is 3. Patron's are able to load more chunks depending on the tier.