After I read the dr.Ross'book "Freshwater stingrays" and after I discussed on this forum about the qualification of my tank to keep a stingray, I've decide to publish a summary of the technical characteristic of my tank and the fish population.
1) The tank is a 576 litres, 120 (l)x60(w)x80. It has an external filter (an Askoll, 1300 l/h pump, biological and mechanical filtration) and a modificated pump (approximately 1000 l/h, modified to do a mechanical filtration). There is also an internal warmer (300 watt; in a strategic position) and a bubble-maker (275 l/h). Lighting: 2 80 W. HQL.
2) The water parametres are: pH 6,5, hardness 3 KH/5 GH, ammonia 0, nitrites 0, nitrates 5 mg/l, conductivity 250 microSiemens. The water is change twice a month (100 litres every change with 3/4 osmosis and 1/4 tap water).
3)The population is: 1 Gobiosoma broussonnettii (21 cm.), 1 Crenichicla sp. xingu (approximately 14 cm;male), 1 Pantodon bucholzii (app. 8 cm;male), 1 Agamyxis pectinfrons (app. 18 cm;female?), 2 Polypterus palmas polli (female app. 25 cm.; male app. 15-20 cm.).
3) Plants: some Anubias, two Echinodorus and one very big Microsorum. There is a great population of Pistia (frequently pruning). In the future I'll buy other Echinodorus and some Vallisneria to improve the water quality (that I'll put in some apposite site around the glasses;see below);I'll buy they three weeks before the ray.
4) Decoration: some roots; two little river stones (not chalky). Bottom: 5-10 cm. of fine sand (<0,5 cm.). The decoration is only around the glasses, so there is a 80x 60 free-swimming (and free-burying) area.
5) The rays I want keep is a "P. reticulata" (and so it can be a dummerillii, a orbigny or other
). Sold such medium-sized (diameter 15 centimetres or more I think). Quarantine in the fish shop (I've make a deal with the dealer-sorry for the play on words 
) for two weeks. It'll be accustomed in the fish shop to eat bloodworms, and the dealer will try to reproduce the water parametres of my tank.
So...some suggestions?
1) The tank is a 576 litres, 120 (l)x60(w)x80. It has an external filter (an Askoll, 1300 l/h pump, biological and mechanical filtration) and a modificated pump (approximately 1000 l/h, modified to do a mechanical filtration). There is also an internal warmer (300 watt; in a strategic position) and a bubble-maker (275 l/h). Lighting: 2 80 W. HQL.
2) The water parametres are: pH 6,5, hardness 3 KH/5 GH, ammonia 0, nitrites 0, nitrates 5 mg/l, conductivity 250 microSiemens. The water is change twice a month (100 litres every change with 3/4 osmosis and 1/4 tap water).
3)The population is: 1 Gobiosoma broussonnettii (21 cm.), 1 Crenichicla sp. xingu (approximately 14 cm;male), 1 Pantodon bucholzii (app. 8 cm;male), 1 Agamyxis pectinfrons (app. 18 cm;female?), 2 Polypterus palmas polli (female app. 25 cm.; male app. 15-20 cm.).
3) Plants: some Anubias, two Echinodorus and one very big Microsorum. There is a great population of Pistia (frequently pruning). In the future I'll buy other Echinodorus and some Vallisneria to improve the water quality (that I'll put in some apposite site around the glasses;see below);I'll buy they three weeks before the ray.
4) Decoration: some roots; two little river stones (not chalky). Bottom: 5-10 cm. of fine sand (<0,5 cm.). The decoration is only around the glasses, so there is a 80x 60 free-swimming (and free-burying) area.
5) The rays I want keep is a "P. reticulata" (and so it can be a dummerillii, a orbigny or other
). Sold such medium-sized (diameter 15 centimetres or more I think). Quarantine in the fish shop (I've make a deal with the dealer-sorry for the play on words ) for two weeks. It'll be accustomed in the fish shop to eat bloodworms, and the dealer will try to reproduce the water parametres of my tank.So...some suggestions?
)...