HELP with my designed experiment! I am not sure if its a controlled experiment?? PLEASE ANSWER?

My experiment in the beginning was to test the toxicity of vitamin c on cells. I used two different types of vitamin c: (lab grade) sodium L-ascorbate and store-brought vitamin c crystals. I placed paramecium into culture jars then in each jar i put one type of vitamin concentration. The concentrations i used were: 10000, 5000, 1000, 500, 100 and distilled water control and a control with just paramecium.


See Im wondering if i made a mistake and made this experiment a 2 variable experiment with the 2 types of vitamin c (being the first) and the different concentrations (being the second) since i was testing how toxic vitamin c can be to paramecium cells.


So is this a 2 variable experiment or controlled and if so how can i change it to make it a controlled experiment??? Thank you!!!


Im sorry but im very pressed for time so if you could help me in anyway TODAY that would save my life because i have a paper im writing on my research so i truly need to knoHELP with my designed experiment! I am not sure if its a controlled experiment?? PLEASE ANSWER?
Your design is controlled, but with multiple subgroups. Using two forms of vitamin C is the least of the confounding variables, and the results of your study would have been only a starting point for further study rather than a definitive study in any case, so you needn't beat yourself up over this one.