Rot zones in the bottom gravel
In spite of having about 15 trumpet snails (60 cm aquarium) and siphoning, I discovered another large rot zone yesterday. What can I do? I already have some waterweed and hornwort plants. The bottom gravel consists of a mixture of sand and coarse gravel.
first of all, 15 trumpet snails would be very few - possibly there are many more of them in the aquarium without being noticed!
Regardlessly, the rot zone should be checked carefully. Bottom gravel clogged by organic waste or decomposing root remainders of a dead plant are the most common causes.
Simply remove rotting roots - you should combine this with a larger partial water change during which you clean the rot zone location in bottom gravel very carefully with a sera gravel washer.
In case the rot zone has formed because of deposits within (coarse) gravel, it is advisable to replace the bottom gravel with finer material. This is the only real solution for removing the problem cause. Trumpet snails can hardly loosen coarse gravel.
But I need the gravel as the plants are always floating at the surface otherwise.
You can also simply weight the roots of the plants (planted in sand) down with some larger pebbles on the sand surface, this is usually sufficient.
Dr. Bodo Schnell