Custom Alert Levels

Would it be possible to set custom fill percentages on storages? The default increments of 25% are good, but for something like nuclear waste, I personally would like to be able to set the threshold to something like 97%. This would let me leave it idle longer before I had to worry about building/activating the next storage in the chain.
If truely custom input isn't possible/practical, changing the increment levels to 5% would be close enough.