The assumption may be reasonable, but it was not evaluated*

*Actual second sentence of the Discussion section of a paper by a well respected scientist.

I started my experiment yesterday, and now I'm sitting around waiting for the catastrophic failure. Because every experiment has one. If the failure happens after next week, it'll be too late for me to restart the thing this season, and I'll be stuck doing more lab work next summer when I actually plan to be writing and defending. There were quite a few opportunities for failure yesterday:

1. The tanks could have failed to hold water. There was a small leak, but I fixed it. An even smaller leak has become apparent, but it's slow enough that I don't care, and it's in the tank that holds an extra replicate. If I lose the whole tank, it's no big deal.

2. The jellyfish attempted to evade capture. After the massive slap of jellyfish that foiled my plans last week (yes, a group of jellyfish is called a slap), this didn't seem very likely, but I managed to round up the necessary 18 after much effort.

3. There was some concern about whether there was going to be water to fill the tanks with, but in the end that worked out too.

So now I'm just sitting here waiting for the other shoe to drop.