How its working? Between indicator liquid (which is dkH 4 -
So initialy the color of the solution is blue (not enough CO2) and is changing to green when is ~30ppm, changing to green-yelowish if the level is too high.
The shape of drop checker might be different, but idea is always the same.
Step 1: Parts and assembling
small black cup (don't remember exactly where it came from, shampoo or something?)
small vial (my is made from plastic)
small sucker (unnecessary from electronic thermometer , black will be better)
piece of neoprene (my was from mouse pad)
some glue or double sided tape
scisors, scalpel, etc
First of all I've adjusted the black cup height. Then lenght of the transparent vial has been adjusted to slightly longer than black cup, to make the indocator inside visible. (see schematic cross section)
Next stage was stick the neoprene blocks from both sides of the transparent vial. The blocks was used to keep vial in place inside the black cup. (still has to be a gap so the air inside has got contact with indicator and water inside tank)
Than hole for sucker has been drilled, and that basically was end of the story.