CO2

Which is  more effective  for the growth of aquatic  plants,  lower  carbonate hardness or lower total hardness?

In the aquarium industry, carbonate  hardness (KH) refers to the level of bicarbonate  ions  (HC03-)   in  the water; while total hardness (TH) and general hardness (GH) refer to the level of calcium ions and magnesium ions contained in the water, respectively.

If the pH and KH of the water decrease, more carbon dioxide, which is dissolved in the water through CO2  injection, takes the form of free CO2 In view of the fact that free CO2 is more easily absorbed by most aquatic plants, it will be easier to grow aquatic plants in water that has a lower KH concentration. For total hardness (TH), most aquatic plants do not grow well in hard water containing high calcium and magnesium ion concentrations, and therefore it is better to maintain soft water at a lower total hardness in the aquarium for healthy growth of aquatic plants. By using Aqua Soil as a substrate material, you can lower the carbonate hardness and total hardness in the water and obtain water quality that is most conducive to the growth of aquatic plants.

Reverse Osmosis (RO) is one of the most efficient ways of reducing water hardness and works without the use of any chemicals or harmful products. In fact, Reverse Osmosis will remove between 95 and 99 % of chemicals, minerals, and other dissolved particles, leaving behind pure clean water

If the pH level is 6.4 before CO2 injection, it can be assumed that the reagent of your Drop Checker did not change color because the impact of water acidification from Aqua Soil is greater than the change of CO2 level.

In this case, it is advisable to do a water change to bring the pH level of the tank water closer to neutral, and then add the tank water to the reagent for installation of the Drop Checker.

The Canister Filter can provide an adequate filtration capacity if Biological Media like Bio Rio, a filtration medium for biological filtration, is used as the ultimate filtration medium. Biological media features a porous structure which is optimal for microbial activity as well as mineral contents, thanks to its natural ingredients.

As for cloudy water, most likely this is caused by the 24-hour CO2 injection and absorption of CO2 into the filter, as you mentioned. It is sufficient to carry out CO2 injection only while the lighting has been on for about 8 hours. During the  night when the  light is switched off, CO2 injection should be stopped and aeration should be performed to get rid of excessive CO2 in the water.

This is because the oxygen  in  aquariums  sometimes  becomes insufficient  because  the flourishing aquatic plants respire during the night. Lack of oxygen affects  microbial  activity  which  impedes improvement in water clarity.

For these reasons, locate the water inlet of the filter and CO2 Diffuser in a place where CO2 is not absorbed from the water inlet of the filter

The size of the tank determines its capacity, which in turn determines  the  appropriate  amounts  of substrate  materials  and  filtration  system required.  The same applies to CO2 injection volume. CO2 volume in water is expressed in density (mg/ltr ).  As you can see from this unit, a constant density cannot be achieved unless the amount of CO2 is increased in proportion to the rise in water volume .

For example, to always maintain a CO2 density of about 20mg/ltr  to promote the Photosynthesis of aquatic plants, 200mg of CO2 must be dissolved in water if the water volume is 10 Ltr. If the water volume is 100Ltr, the amount of CO2 to be dissolved in water will be 2,000mg.

This means the greater the capacity of the aquarium tank which determines water volume, the greater the amount of CO2 to be injected. There is a standard level of CO2 injection volume for each tank size, though the CO2 injection volume in fact varies with the pH level of water and density of aquatic plants. For instance, the capacity of a 90cm tank is three times higher than that of a 60cm tank and therefore the required CO2 injection volume for the 90cm tank will be almost tripled.

The CO2 injection volume can be checked with a CO2 Glass Counter or Bubble Counter by “the number of bubbles per second”. However, the CO2 diffusion efficiency may vary depending on the size of the Diffuser which discharges CO2 into the water.