How much do you want to shoot is the question..
you can put 1000ius in a ml of water bro, put 2000 in a ml, put 5000 in a ml. You can put 10ml's per 1000 ius, why? I dont know, but it seems youre curious but you can dilute it to hell if you want and shoot a ton of bac water with very little chance of hcg coming along with it.
I get mine in 1500iu vials with 1ml of solvent. The only real downside to a higher concentration is that more HCG is left in the syring when you're finished. Either way, though, it's negligable if you use a slin pin to inject it.