Completely new setup after algae trouble? / Snails in the aquarium


I have had my aquarium for 9 months and now want to set it up anew because it has become very, very green. It looks like 'hair' about 1 cm (0.4 inches) long. What is this? Are these algae?

I do not recommend a completely new setup. This would only destroy useful biological systems that build up slowly - it takes about 1 - 2 years until an aquarium is really biologically stable in itself, there is no way to avoid this.

The green "hair" is certainly algae. The key to an aquarium with few algae is mainly to regulate the nutrient ratio (nitrate and phosphate) in a way that the plants are just correctly provided with nitrogen and phosphorus, but nothing is left over for algae. This is actually the key to all algae problems. This often goes along with an amount reduction of these nutrients. Controlling the phosphate and possibly iron levels is important especially in case of beard and brush algae.

You can achieve nutrient reduction by

* reducing the number of fish/the food amount

* abudantly adding fast growing plants

* generous partial water changes with water low in nitrate and phosphate (!)

* possibly adding a slow flux filter that breaks down nitrate

* especially in case of brush algae: Using sera phosvec Granulat in the filter

* not using care products that contain nitrate and phosphate

* creating optimal growth conditions for plants (good lighting, mineral and trace element fertilization, possibly CO2 fertilization, suitable bottom ground etc.)

This requires some patience, it can take several weeks until a visible effect takes place.

Would it be good to have some snails in the aquarium? If yes, which species?

Trumpet snails (Melanoides tuberculata) are in any case useful, they loosen the bottom gravel and avoid sticking. Physa and ramshorn snails (Physa and Planorbarius spp.) are also useful scavengers. Neritina species are very attractively colored and also do not cause any harm. This genus does not multiply in freshwater. They do lay eggs, but these do not develop.

Almost all snails are quite useful in an aquarium and not harmful at all. After all, only very few snails cause harm - mostly applesnails from the genus Marisa, which eat plants right down to the stems.  However, these snails (they do not look like other applesnail species but look similar to oversized ramshorn snails with a stripe pattern) hardly ever get into an aquarium accidentally.


Best regards

sera GmbH

Dr. Bodo Schnell



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