My second piece of general advice is that no single experiment is going to be perfect, and, because of that, you should consider designing a series of experiments that reinforce each other.
Isiqephu sami sesibili seseluleko sokuthi akukho luhlolo olulodwa oluzobe luphelele, futhi, ngenxa yalokhu, kufanele ucabange ukuklama uchungechunge lwezivivinyo eziqinisa omunye nomunye.