The Uses Of Aquarium Peat
by Paul Barrow
First published in the TTAA Newsletter

Peat is a versatile substance in the aquarium, it is a mainstay for breeding annual killies, it can be used as a substrate for breeding egg-scatterers, it is one of the best filter medium for acidifying water and it is a good alternative to gravel as a decorative substrate. It does, however, need careful preparation before use, which is explained in ‘ Preparing Peat for the Aquarium’
Uses Of Peat
 Peat It makes an excellent base medium for spawning certain egg-scatterers such as barbs and characins. It is thought by many, that the organic hormones in the peat are similar to those flushed from the forest floor during the rainy season, and it is this, which encourages many fish to spawn in peaty water. A depth of 10-20mm will catch the falling eggs, and hide them from the hungry parents. Eggs falling into the peat are also protected from light, a killer of tetra eggs. The peat’s acidity reduces the chances of fungal attack, and its organic content encourages infusoria to grow, which provides food for the newly hatched fry. The fastest growing fry I have ever seen were Barbus pentazona; their extraordinary growth was due to the constant meal provided by a cloud of infusoria hovering over the peat covered base. 
Killifish
Peat is essential for breeding annual killies which, depending on species, needs a depth of between 25mm and 50mm to dive into. To collect their eggs, simply siphon all of the peat out of the tank into a fine meshed net and allow it to dry-out for a few hours. Place the dried peat into plastic bags printed with the species name, date of drying and expected time of hatching. Make sure the bags are tightly sealed and stored in a warm, dark place.  When it comes time to ‘wet’ the eggs, place the peat in a suitable container and dribble aged water over the top of the peat. This method reduces the amount of peat that will float. Putting it straight into a container of water creates an impenetrable covering of floating peat that prevents the newly hatched fry from reaching the surface to take their important first gulp of air. No matter how long the peat is left floating on the top of the water, it will never sink! Two important points to remember when dealing with the peat used for breeding killies are:
i) always sterilise the tank before introducing new species,
ii) always boil the peat before it is re-used for spawning.
Both of these things kill-off the old eggs and prevent hybridisation between related species (most females within a genus are similar). Prepared peat can be used in filters to acidify water and, as an added advantage/disadvantage, it turns the water brown. To prevent peat being blown out of filters, it must be held in mesh bags, or sandwiched between layers of filterwool. Some forest fishes thrive in this dark, peat coloured water and show off their best colours, but is not always desirable and the brow colour can easily be removed by filtering through activated charcoal.