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 😉
If your drop checker is staying blue, there is almost zero CO2 in your water. But here’s the thing…
Drop checkers don’t actually monitor CO2, they monitor pH. When you add CO2 (an acidic gas) into your tank, it reduces the pH. When your drop checker is showing blue, it’s telling you the pH is around 8 (far too high for plants). As you inject CO2 your drop checker will change colour (assuming you’re injecting enough CO2). The solution will begin to look a bit more green. When it hits a nice shade of green it means your pH is about 6.8 and your CO2 levels are 30ppm (parts per million). Green is the ideal colour to aim for and what you need to strive for.
But all too often hobbyists don’t inject ANYWHERE ENOUGH CO2. In a 100L tank, you need to start with 1 bubble per second for 8 hours a day.
Any changes you make to your CO2 flow rate needs to be done slowly. Remember your drop checker operates in the past – it’s not like a test kit in the respect that you take a sample of water and do a reading. There’s a delay of about 2 hours – this is how long it takes for your drop checker to change colour. So if you tweak your CO2 levels now, wait 2 hours, then see what colour it has changed to.
Always make small gradual changes to CO2 flow rate, otherwise you could overdose your fish with CO2 and see them gasping at the surface of your tank.
So what’s different about this one? Not a lot to be brutally honest but then, who cares? It performs the job it needs to and in a planted aquarium (which uses pressurised CO2), a drop checker needs to become your best friend. You need to pay a lot of attention to it and see what colour it’s changing to.
Drop checkers work by monitoring your pH (not CO2 as most think). You see pH levels are effected by CO2 (which is an acidic gas). The more CO2 you pump into your aquarium, the more the pH drops. A drop checker shows this change by the colour reading. Yellow = too much CO2, Blue = too little CO2. Green = PERFECT!!
Your goal is to maintain a lovely green colour so change your CO2 flow rate to suit. When you achieve that magical green colour, it indicates you have the desired amount of CO2 in your water (30ppm = 30 parts per million). Plants love this level of CO2 so give them what they need.
Actions speak louder than words – I hear what you’re saying! So I’ve done another YouTube clip for you which briefly explains the importance of a drop checker in a planted aquarium when you are using pressurised CO2.
Drop Checkers are an important piece of equipment in a planted aquarium. In fact without a drop checker how do you actually know what your CO2 levels are? They work by measuring the pH levels in your aquarium. A small amount of test reagent is placed in your drop checker and changes colour according to your CO2 levels. The ideal colour to aim for is green and if you have too little CO2 it becomes blue and too much, become yellow.
Available in a variety of shapes and sizes, some glass, some plastic but they all do the same job. The only difference is that most of them are supplied with a reagent that doesn’t work properly and as a result will give false readings. If you have a drop checker and you use tank water and an orange reagent to measure your CO2 levels, then you need to change (this is the old fashioned/incorrect way) but we’ll get onto that shortly.
All drop checkers need to use 4dkh bromothymol blue solution. This solution is the most accurate on the market and once placed in your drop checker provides accurate results. In a planted aquarium the desired CO2 level for optimum plant growth is 30ppm. When your aquarium has this amount of CO2 in it, your drop checker will turn green – this is why it’s so important. So why shouldn’t you use tank water and the orange reagent that most drop checkers come with?
Tank water contains a variety of acids and alkalines some created by fish and shrimp, others added by hobbyists in the form of fertilisers for their plants. Therefore by using tank water in your reagent you’re adding a solution that is already changing and this is no good if you want accurate results – you need to start with a stable base level and go from there. This is where the 4dkH bromothymol blue solution comes in handy.