Sad, neznam kakav je taj JBL-ov, ali ja u svoj (stakleni = eBay) stavim malo (oko 1ml) KH4 otopine i par (4 kapi) reagensa... i to u akvarij... i to radi... svakih 4 tjedna promjenim smjesu u njemu i nikakvih problema
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sad sam našal na netu taj neki kockasti JBL-ov... koliko vidim uz njega dobiješ otopinu (KH4) i reagnes... u uputi piše koliko otopine ide nutra i koliko kapi reagensa... zatvoriš, okreneš, priljepiš u aq i to je to...
1.Using the syringe I pull 1.5 ml of the 4dkH from the bottle and transfer to the clear plastic vessel.
2. Squeeze 3 drops of the reagent into the vessel and shake gently. The solution will turn a blue-green indicating a pH of around 7. If you notice in the photo, the black base has a white plastic band against which the colour of the reagent can more easily be seen. As cheesy as it appears, this is a brilliant feature. When the checker is in the tank it's difficult to distinguish reagent colours against tank background and plant colours.
3. Invert the black base so that the white plastic end is inserted into the plastic vessel and snug up the assembly. A bit of silicon grease around the o-ring will make it easier to separate later.
4. Now invert the assembly being careful not to spill the fluid so that it looks like this (your drop checker can double as a spirit level in a pinch):
5. Next, holding it level, mount the checker anywhere on the front glass inside the tank so that air is trapped in the vessel.