Stop feeding them SlimFast !!!

I really dont know the answer to this. Perhaps in the process of turning dirt into plant discards some of the minerals somehow.

Interesting point though !!! I'd like to hear an answer to that one...

I don't think I ever heard someone ask that question before either... I don't even know your logic in weighing the plants and pots.

There are so many variables, perhaps the soil held moisture better at the start, Maybe the pots are lighter now because the root system is well developed and can suck the water out quicker.

How can you possibly measure this accurately ? the only way would have been to completely dry out the soil before you planted the seeds and weigh it. Then re-moisturise it and plant the seeds. You would also have to catch every grain of soil that ran off when you water the plants and put it back in the pot. Flushing for example can remove a lot of matter. Then, in the end you will have to gather every single leaf, stem, root and branch and dry them 100% and but them back in the bucket, then you get your accurate reading.

So there could be a lot of ways to lose weight. But you will never get an accurate reading because you will never find the exact same starting weight because of so many variables.
How can you get the soil to the exact same level of moisture as it was at the start unless you dry it 100% ?

When a plant is left it will dry the soil much more than it was when you first potted.

Good luck with it..

S.L.