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
You want to use as much pressurised CO2 in your tank as possible without causing distress to your live stock. CO2 will make or break your tank and I want you to give you the confidence to use it as it should be used in a high tech CO2 tank. In some cases your CO2 levels will be A LOT more than you think. If you have no live stock you can really have some fun and crank it up. You’ll be amazed at how well your plants will do when you’re let loose…
Most of you are using drop checkers now which is great and just what I have been advising. But many of you get too hung up on the colours – remember the colours are only indicating a pH level change (they don’t really measure CO2). However when your drop checker is showing green (pH of 6.8), you ‘probably’ have good CO2 levels, but I would like you to take it one step further because in some cases your drop checker may need to show yellow. This is fine as long as your fish/shrimp are fine. If they’re showing any signs of distress, lower your CO2 levels.
You really need to maximise the amount of CO2 you can pump into your tank so it will take a bit of playing around but the effects are tremendous and your tank can look like the inside of a champagne glass.
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.
With a high emphasis on flow rate in a planted aquarium I found this latest video which Mark Evans shot, very interesting.
The general idea is that you filter 10 times the tank volume of water per hour so if your tank is 100L, you would look to have a filter that filters 1000L per hour. Fairly straight forward right? But in a larger aquarium is this necessary? I always thought it was until today. Mark’s aquarium is large, 363L. Previous calculations would mean the filter/s would need to move 3630L per hour but it’s quite a lot less this time and the flow rate is 2600lp/h and as you can see from the results, it’s pretty incredible. Flow rate is much slower but with no negative impact.
Interestingly enough the CO2 is also fed into the external filter via the inlet and the results mean that you don’t have thousands of tiny bubbles floating around the tank. The diffuser is an UP 16mm Inline Diffuser – in the past these have always been plumed in on the outlet but I do like the idea of not having to look at all the bubbles…
A lot of people ask where they should place their powerheads or filter outlets in order to get the right sort of water movement and as you can see from the clip, a large spraybar is positioned which pushes the water across the tank and at the opposite side is a lily pipe positioned very close to the water surface. Now I’m not sure if this is to keep the surface polished or if it’s another reason. Maybe if Mark reads this post he could enlighten us What I do like to see is some water movement at the surface and it’s clear that there is a gentle ripple – this makes the water shimmer a little too along with the help of his metal halide lighting. In the past hobbyists were keen on maximum Co2 absorption and kept the surface almost still which caused nothing but problems. Dust would build up very quickly and then this could turn green blocking off light.
I also like his positioning of the drop checker. Right under the spray bar – odds are he won’t have a great deal of flow around there so if the drop checker is green there, you can bet it’s bang on for the rest of the aquarium.
All in all, you can see Mark does things a little differently to most hobbyists and this is why he gets such super results. He tries, experiments and learns and his skills are getting better and better all the time.
I would love to hear what other people think of his tank and also where they position their drop checker.
Most of you are pretty familiar with drop checkers and I have written about them on here before. If you’re not (do a quick search on our blog), they’re a must have product for a planted aquarium without any question of doubt. They measure your CO2 levels in your planted aquarium.
All drop checkers work in the same manner but all differ in looks and shape and the new Cal Aqua Nano Drop Checker has to be one of the smartest drop checkers I have ever seen. It’s so delicately made and so tiny at a mere 3x3cm you could easily lose it in your planted aquarium. Whilst you don’t of course want to lose it, keeping as much equipment out of the tank is the idea as it distracts from the aquascape. Any equipment in the tank should ideally be glass (where ever possible). This drop checker comes with everything you need too – 15ml of bromo blue which means that when your solution turns green, you have the ideal CO2 levels in your planted aquarium (30 ppm). It also comes with a clear suction cup.
Although aimed towards smaller aquariums I personally think it’s suitable for all sizes of aquariums from the very small to the very large. Positioning wise, try placing it under your filter outlet – this will give you a really good idea as to your CO2 levels in your tank.
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.