Very probable the filter was not adequate.
This depends on your experiment and glassware.
A hypothesis.
A set of controlled observations that test a proposed explanation are known as an experiment. The proposed explanation is known as the hypothesis of the experiment.
Hypothesis =)
The explanation supported by many experiments is called scientific theory.
The conclusion
The hypothesis is a personal explanation of what youbelieve will happen during an experiment before you proceed in doing that experiment.
Be clear about the purpose of the experiment.
A Hypothesis
More trials of the experiment.
More trials of the experiment.
understandable, clear