I bet it would help alexinoz if some people could post their excel spreadsheets so he can see what data people usually collect.
BRAND NEW NEVER OPENED NEVER USED!
"EHEIM Quick Vac Pro Automatic Gravel Cle ...
Everything is brand new, tank only lightly used
for aquascape. I purchased a larger tank for my
Offering a beautiful blue and yellow damsel.
Approx. the size of a gold dollar coin. He's
being a b ...