99% people need this article about how to judge the water quality of straw cans.

First, let's talk about carbon dioxide and ph value. Everyone likes to measure the flow of carbon dioxide with several bubbles per second, but this method is not suitable for me (it is not easy to operate, so you don't know whether the carbon dioxide in the water is sufficient or excessive. Your information can't be obtained intuitively through the changes of creatures in the tank, but only from the experience of others. My bubble counter is very unstable and I can only see the approximate number of bubbles. And it's hard to control But this does not mean that the flow of carbon dioxide cannot be controlled. I think a very accurate method is to control co2 by detecting ph value. First, slowly open the cylinder to the maximum, and then control the flow to a relatively stable state by constantly trying to adjust and fine-tune it (measure the ph value every 1 ~ 2 hours, and finally control the ph value between 6 and 7, which basically means that the adjustment is in place). At this stage, you will find that the grass is growing vigorously and in good condition, and almost all the grass is bubbling. At the same time, there is no floating head phenomenon of fish and shrimp. Once the floating head phenomenon of fish and shrimp is found, it means that the water in this tank is too acidic (or the Ph value is too fast), so it is necessary to appropriately reduce the co2 flow or turn it off first.

If my Shijing tank (1 m2 tank, Yingde stone) does not add CO2, and the ph value is above 8, add CO2, and after the ph value drops to 6.6, turn off CO2, and the ph value will return to 8 in a few hours. So in this stone well, I keep CO2 on for 24 hours and keep the ph at 6.6.

As for hardness, Yingde stone must be hard water. Although many friends say that the hardness measured by TDS pen is not hardness, the value measured by TDS pen is basically consistent with what I observed and the result measured by hardness tester. At least as a reference. A few months ago, I opened the tank with tap water. Later, the value measured with TDS pen exceeded 300. It is observed that brown algae are everywhere on rocks and sand. The German hardness measured by the hardness tester is 23-24. Everything points to one conclusion: the hardness is too high. So I measured pure water with TDS pen, and the value was 0. Then I went to the pure water machine and changed water with pure water every time. Now the TDS value is basically around 80. The observation effect is also ideal. When I changed purified water for the first time, because the change was very slow, I could even observe the brown algae slowly disappearing on the stone and the bare stone surface.

However, changing water is not once and for all. Every time the water is changed for about one week, the TDS value will increase by about 40 compared with that when the water was just changed. Therefore, it is necessary to change the water once a week.

Changing pure water can reduce hardness, but it has little effect on stabilizing ph value. Because the ph value of pure water is 7, the ph value can be reduced to near 7 at most. Therefore, it is not expected to stabilize weakly acidic (non-alkaline) water by changing the pure water in stone wells. Moreover, the ph value rises rapidly, and it can rise in a few hours. Maintaining weak acidity can be achieved by controlling the flow rate of carbon dioxide.

About carbon dioxide and hardness

Some people may think that it is unprofessional to put co2 and hardness together, but I did observe the interaction between them many times in the Ishii tank. When the CO2 flow rate increases, the hardness increases rapidly. When the ph value dropped to 5.9, the TDS value rose from 80 to 150 within one hour, and even rose to 202 the next morning. So I must change the water immediately and reduce the flow rate of carbon dioxide. At the same time, I observed that there were traces of slight dissolution on the surface of the stone. My guess is that when the acidity increases, the reaction between the stone surface and the acidic solution increases, resulting in more calcium ions and magnesium ions released into the water, which increases the TDS value.

Even if the ph value is maintained at 6-7, the TDS value will increase much faster than when the ph value is 8, so the frequency of changing water should be increased. As far as my tank is concerned, twice a week is more appropriate. So at this time, one thing needs to be balanced: we need weak acid soft water to supply grass growth, but weak acid water is easy to improve the hardness of the stone jar. Only by being more diligent can we do these two things (seeing soft water on the internet)

200 Ma E Jun1112014-10-31