Thank you very much @CarstenErkel and @gcarver.
I went and bought some fructose (already had the maltodextrin from a previous DIY mix with Gatorade powder) and then ran out of time for any longer rides. I think I also temporarily forgot that my DIY maltodextrin:fructose (i.e. glucose:fructose 2:1) mixture should only really be used for rides of 3 hours or longer. As such, I can put all this stuff away until the Spring as between now and then I don’t think I will ride longer than 2 hours on the trainer in a sitting.
I will probably just use some cheap mix, gatorade maybe, for flavour and carbs at mix at 20g per bottle if going over 1 hour (60-90 minutes).
As for Sodium Nitrate, that is very good to know, I never knew you needed that much to get 1g of Na. I was way under mixing what I thought I was getting but I think it still helped for my leg cramps on longer rides, so maybe I don’t need as much salt as I thought I did. I was only adding about 1 gram of sodium nitrate per bottle, to which I was using Skratch for carbs, which may have been giving me also about 1 gram per bottle I think. So instead of getting 2 grams of Na per bottle I was maybe only getting 1.25 grams. Something to experiment more with next year but good to know it is about 4.5 grams of sodium nitrate to get 1 gram of Na.
Thanks very much.