Yellowing of plants
The leaves of some plants were turning yellow and degrading. The aquarium had enough light and CO2, so it must have been caused by something else. I found out on internet that it could be caused by lack of some nutrients in the water like manganese (Mn) or molybdenum (Mo). On Friday 20/1, I was coming home via Brno so I stopped in the Sklorex store. I bought some fertilizers by Rataj: Mangan+ and Molybden+. I also bought the plants Hemianthus callitrichoides as a replacement for the Staurogyne that were turning yellow and loosing their leaves.
At home I put the new plants into the quarantine aquarium. In the following day, I planted them in the main aquarium. Their planting is not easy. I applied the Mangan+ fertilizer. I added a bit of Molybden+ during the week.
Having passed a week I didn’t observe any significant result of the fertilizer's application on the plants. The new plants turned yellow very quickly. I decided to buy a test of iron (Fe) in water. On Friday 3/2, I went via Brno again, so I bought the Rataj’s Ferrin test in the Sklorex store. They had nice carpet plants Eleocharis pusilla; I bought two pieces of them.
At home, I put the new plants into the quarantine aquarium. Four weeks passed since the last water change so it was the time to change a part of the water. The aquarium had neverrun without water change for so long. On Friday evening I filled an 80-liter aquarium with water to let the water sit. In the following day, I changed 50 liters of water and I also changed 20 liters of water in the quarantine aquarium. I split the new plants into smaller pieces and put them into the aquarium. I stopped applying the carbon sponge in the filtrer. I think it is not necessary in a working aquarium; the producers offer it because people think it is necessary. As it must be changed very often, it is advantageous mainly for the producers.
In the following day, I measured the concentration of iron in the water using the Ferrin test. The sample didn’t color at all, it means the iron’s concentration in the water is very low. I applied the Bioflor fertilizer. But it is necessary to buy some fertilizer to supply the iron.
I finally received packages from China with the products I had ordered on eBay: CO2 diffuser and check valve. The diffuser ismade of glass and has a solenoid inside which allows bubble counting. I've only seen such a type on eBay and it only cost 70 Kč (US$ 3). The check valve is metallic and it cost only 50 Kč (US$ 2). I tried to connect them to an air pump but no bubble came out. They need higher pressure from a bomb. After connecting them to the CO2 bomb, they work fine.
