I was wrong. The shrimp did not die. The day before yesterday I saw all five of them hanging out. Hosanna!
The Ceratophyllum demersum and Egeria densa were dying quicker than they grew. I had to remove them. They are now in a quarantine bucket to see if they can recover at all. I also removed the Java moss. I don’t know if they were dying because of the high temperatures (way over 27 °C), allelopathy, or too much light. The temperatures seem to be down to the more acceptable 26 °C now. I also reduced the illumination duration to 10.5 hours plus 4 hours of indirect daylight (what Walstad recommends as a siesta).
The tank currently contains these plant species:
Rotala indica, or maybe rotundifolia
Heteranthera zosterifolia, shown below
Older specimen of Heteranthera zosterifolia
Heteranthera zosterifolia, new shoots
Also I found a some duckweed and other floating plants which I have put in the tank as well. They are doing ok, but are not growing too much. What is growing, however is brown algae and other algae. They are growing so fast that I have to brush them off the leaves every other day and exchange 50% of the water or more.
Tomorrow I’m getting some snails which should help with eating the algae and dead plants.
Ceratophylum demersum has forked many times and has grown so high that it bent under the water surface. I cut off the larger branches and planted them on their own and I shortened the others by about 50 cm total length. I pulled them out of the soil, cut off the lower piece and planted it again so that the top remains intact. That’s what Foo the Flowerhorn did and that’s what the folks at the aquarium shop told me is normal to do if you want to keep the nice looks of plants.
Above you see the photo of the front of the tank, side and back follow
I did not trim any other plants. The dwarf hair grass has some new shoots but it’s hard to see on a photo. A couple of days ago I saw some fluffy dust-like particles on the leaves of the plants. First I thought it’s something which was floating in the water and now settled on down on the sand and leaves. It turns out that it’s Brown Algae. I had suspected that it could be algae, but wasn’t sure before I read about the various types of them.
Getting brown algae is typical for newly established tanks which are not in balance yet, I read. They occur when there are too many nutrients in the water. Plants can’t use them all, so brown algae have a feast. What helps to lower the amount of nutrients is frequent water changes. I only changed 30% water today, so I’ll change more every day or every other day from now on until I see the brown algae gone.
I also should measure the amount of nitrates in the water. To get rid of brown algae I should have less than 20 ppm of nitrates. A quick and imprecise stripe test is telling me that I have got only around 10 ppm of nitrates, but I’ll do a more precise test soon.