Does accuracy of 4dKH solution matter?

[JamesC]

There are lots of posts around how to make your own 4dKH solution and how important it is to be accurate, but does it really matter?

When you add a couple of mls to your drop checker and then add some drops of bromothymol blue you are in effect diluting the 4dKH solution. I've seen it mentioned on here that some people add a 50:50 mix of 4dKH solution and bromothymol blue so in effectt making the solution 2dKH. This could explain why some people run their drop checkers yellow and don't have any livestock issues.

I always try to have as much solution with as little bromothymol blue as possible so as to minimise the diluting of the 4dKH solution. As long as people are aware of the drop checkers limitations then they are a valuble piece of equipment, just don't believe that the colour you have is a direct value for CO2. They are great for a quick and easy check to make sure that CO2 is working OK. From experience I know what the colour of my drop checker should be so I just need to have a quick glance at it every now and again. To achieve this though I did have to experiment with different flow rates.

So does accuracy matter? Probably not that much as long as it's close. What does matter is that it is consistant so the colour of the drop checker remains the same after each change of solution. I've made up a litre of the 4dKH solution which should last me years.

Food for thought
James

 

[George Farmer]

Nice one, James. I agree.

I actually stopped regularly using a CO2 drop checker since running lower lighting and 'lean' nutrient dosing in my set-ups, meaning I can run lower CO2 without issues. I would be very surprised if my CO2 was over 20ppm.

It makes perfect sense for me; fish are 'happier', less CO2 and fert usage, slower growth, yet no algae issues.

However, I do usually use one initially after setting up a new tank when obtaining an approx. max CO2 bubble rate. For example, if 2 bubbles per second give me a lime green drop checker solution then I know that's the max. bubble rate I should run, and may drop it to around 1 bubble per second.

 

[ceg4048]

Yeah, I agree. A dropchecker is not the most accurate measurement device anyway for a couple of reasons, not the least of which is it's poor response time lag, and it certainly doesn't tell you what's happening within the plant beds. CO2 is always distributed unevenly within the tank anyway, but it is a rough, inexpensive guide and is certainly more accurate than measuring tank water (which we know is corrupted) or counting bubbles, or having nothing at all. It's the best of a bad lot I'm afraid. So whether your dkh solution is slightly off, it's not that big of a deal. As you say James, consistency is the name of the game and observation of the plant and fish response is more important.

As with any tool, one needs to be cognizant of the limitations and advantages of this tool.

Cheers,

 

[spider72]

Other downside which can occur and should be noted while using dropchecker is when aquarist is spraying mist of CO2, what I am doing for example. I have noted that checker is turning yellow quite quick with no effect on fish or shrimps. This is probably because CO2 mist is entering diffusion chamber. Bubbles are very small, but contain 99% of CO2 and are putting checker reading off.
As said already dropchecker is a good guide, but has not final say about CO2 level in the water, plants have .

 

[plantbrain]

Unless the color resolution of the pH measure is also accurate, it's not critical for the KH solution to match and be accurate that much either.

So if you used a pH meter probe in the 4 KH solution, then it would need to be accurate since you have good pH resolution/accuracy, but those color pH charts are of 3 types: yellow/green and blue over what? A pH range of maybe .6? or more?

KH really is less an issue then.
Folks put a lot of faith into pH/KH or drop checkers etc.

I do not.

Regards,
Tom Barr

 

[Themuleous]

This could explain why some people run their drop checkers yellow and don't have any livestock issues.

Thats an interesting thought James, makes perfect sense though.

Does this mean we could make our own solutions without worrying to much about the accuracy of the solution?

Sam

 

[Aeropars]

I always make my own solution. Never bothered to buy it, especially concidering its cost!