Ok so I was planning on giving the cider three weeks but I took a test reading just in case it was ready, due to the low sugar content in the original mix. The final reading was 0.998 which means I'm now sterilising my bottles, ready for bottling. I'm thinking of splitting the batch into two when bottling and only carbing half of them. The cider ended up medium dry, which is good. I think it calculated out to about 4.4% but I'm not sure.