If you have a drop checker...
and you really should (assuming you have a pressurised CO2 system) then making sure you have the correct positioning is sooo important. Too many hobbyists place their drop checker in the top right or top left of their tank. Maybe this is where you have yours? And I can see why too, because if you look at any decent planted tank in a magazine for example, they have it positioned just there but only because it 'looks right'. Remember a drop checker is a measuring tool and whilst they do look nice and aesthetically pleasing in certain areas, the correct positioning is not there.
So where do you place it?
Your drop checker should be located in the bottom right or bottom left, about 2-3cm off the substrate. CO2 rises so when a drop checker is placed near the top of the tank you get a false reading (and it will appear you may have more than enough CO2). A lot of problems in a planted tank arise from insufficient CO2 levels due to not using a drop checker or incorrect positioning. Customers email me 'but my drop checker is showing green' and they proceed to tell me it's located near the top of their tank. Soon as they move it down the bottom, the colour changes to blue. So, if you position your drop checker correctly (at the bottom) and you know the bromo blue solution (very important) is green, you can rest assured you have the correct CO2 levels. All you then need to be concerned about is water distribution and making sure those precious CO2 bubbles are going everywhere (and I mean everywhere) but that's a email for another day ;)
