Gush CO2 indicator solution

**furyprix** · 18th Apr 2014, 21:06

Hi bros, would like to know if I have to add dk4h solution to this to make it work? Because on the item, it says 'mix 1:4 parts with water, ready to use'.

i have installed it in my tank for ~1hr but I have not seen the blue color indicator change color. I'm running a 2ft with DIY co2. Just changed the yeast and sugar mixture yesterday. It's running at >1 bps.

Anyone had experience using this product?

**Urban Aquaria** · 19th Apr 2014, 00:16

If the instructions mention to mix the reagent with water, it means you need to mix it with 4dkh water. Just using the reagent on its own will not yield any results.

Alternatively, you could also just buy the pre-mixed indicator solutions from brands like Ocean Free or ISTA, no need to mix and much easier to use.

Here is a thread i posted on those pre-mixed solutions: http://www.aquaticquotient.com/forum...cator-Solution

**furyprix** · 19th Apr 2014, 00:40

i did mix it with 4 parts of tap water. to my surprise, it turned green after a little longer after i posted this forum post! i suppose it works? :O

**bennyc** · 19th Apr 2014, 09:07

The color may change but the results are not accurate. It would be strange if you have already considered and therefore bought a Co2 indicator but you are okay with the end result is not fully correct.

Co2 indicator takes time to change. The results are not fast or immediate. I would highly recommend buy 4dkh water for a more cconfident reading or like Urban recommend (which i am using myself too) get one already premixed, much lesser hassle.

**Urban Aquaria** · 19th Apr 2014, 10:43

Originally Posted by furyprix

i did mix it with 4 parts of tap water. to my surprise, it turned green after a little longer after i posted this forum post! i suppose it works? :O

The Co2 indicator readings are based on the changes of the pH in the solution (Co2 lowers pH in the water).

Unless your tap water has a known and stable starting pH/kH value, the indicator readings with that tap water mixture will be inaccurate. Therefore even if the mixed indicator solution turns green, the actual Co2 ppm level may turn out to be too high or too low due to the uncertain water pH and kH levels.

4dkh water has the fixed values of 7.0 pH and 4dkh (also referred to as reference solution), which when mixed with the reagent, will give the correct results based on the pH/kH charts:

Source: http://www.littlegreencorner.com/tipsdropchecker.html