What in the world is a "Pleco" ?
They are a breed of fish. The scientific name is Hypostomus plecostomus (known commonly as a sucker fish) They are freshwater fish and are native to tropical Central and South America.
They are capable of consuming large quantities of algae. Plecos' also consume anything that is left on the floor of the fish tank such as uneaten fish food and solid material that may settle in the corners of the tank or around structures such as the submersible pump. They do a really good task of keeping the pump exterior clean.
These fish are a very useful addition to any Aquaponics system assisting in the processing of waste material from the principal fish colony that you keep in your system.
Recently we added one Pleco to our floating raft system fish tank. This particular fish tank is located in the greenhouse and is subject to getting sunlight all day every day. It has become a standard maintenance practice to scrub the sides and bottom of the tank every couple of weeks in an attempt to keep the build up of algae under control. It is a neverending task and one that we fall behind on at times.
Placing the Pleco in the tank has had amazing results. The tank is now very clean both sides and bottom.
The Pleco gets on well with the Jade Perch in the tank. I guess we will find out over time if it remains that way. As the Pleco gets some real size the "balance-of-power" may shift. It would appear that this is a very good way to keep the tanks clean in a home Aquaponics system. We have obtained another 15 Plecos and have distributed them around our various systems and are enjoying seeing their work expand each day. Every morning it can be clearly seen the progress made the night before as they work their way around the bottom and sides of their new home.
The most interesting will be the progress of 10 very juvenile fish in to the raft tank on our floating raft system. They will grow fast over summer and should do well in their new surroundings. Very fine solids drop out of the water as the water passes slowly through the raft tank depositing on the bottom in a layer about 6mm (1/4") deep. This material accumulates to this depth over about a 6 month period. The main filter system does not catch all the very fine material and this accumulates in the bottom of the rafts.
I am confident that the Pleco fish will clean all this up as part of their "daily bread". This will effectively process the very fine solids and keep the nutrients in the Aquaponics system to be taken up by the plants. The only thing left behind by the Plecos is their own waste material. This material will eventually move through the system and be trapped by the filter system. The important thing is that the nutrients are retained in the system rather than being cleaned out and discarded.
I think of my Plecos' as "Living Filters" for my Aquaponics system