The credit system doesn't mean that you can’t use Chemicalize for free. We provide several features (basic calculations, web page view, search) free of charge and give 100 free credits monthly. If you turn off the calculators that are not relevant for you, you can save your credits. With default settings (all calculators on) one calculation cost is 11 credits but if you want to see only the isoelectric point and turn off others it is only 1 credit.
Furthermore if the fee credits are not enough for you, because you want to use Chemicalize in a larger project, let us know, send us a short description and we can give you some special academic offer.