Efficient oxygen input by flow pump

​Each spe­ci­es of fish has its own pre­fe­ren­ces for per­fect flow con­di­ti­ons: some fish spe­ci­es pre­fer per­ma­nent cur­r­ents and „surf“ in them, others only move to spawn in cur­r­ents and others pre­fer to live in calm waters. The back­ground is the oxy­gen demand that every fish has. Howe­ver, one spe­ci­es needs more, the other less O2. A stron­ger cur­rent means that more oxy­gen can reach the gills. In a recir­cu­la­ti­on sys­tem, the­re­fo­re, the right water move­ment must be cho­sen, and the requi­red amount of oxy­gen pro­vi­ded, depen­ding on the spe­ci­es used. The aim is ther­eby to achie­ve both the flow and the oxy­gen input as cost-effi­ci­ent­ly as possible.

Oxygen saturation in recirculation systems

The use of flow pumps pro­mo­tes the well-being of the ani­mals and pre­vents stress, espe­cial­ly during peri­ods of high acti­vi­ty and thus high oxy­gen con­sump­ti­on (e.g. during fee­ding). The maxi­mum solu­b­i­li­ty of oxy­gen in water depends on the water tem­pe­ra­tu­re and can be found in tables. In princip­le, more oxy­gen can be dis­sol­ved in col­der water than in warm water. In our clo­sed recir­cu­la­ti­on sys­tem, the water tem­pe­ra­tu­re average is about 22°C. At this tem­pe­ra­tu­re about 9 mg/l oxy­gen can be dis­sol­ved, which cor­re­sponds to a satu­ra­ti­on of 100%. For many ani­mals, howe­ver, values of about 6 mg/l of dis­sol­ved oxy­gen are suf­fi­ci­ent with the right cur­rent, some­ti­mes even less depen­ding on the spe­ci­es. This cor­re­sponds to less than 70% satu­ra­ti­on. The­re­fo­re, we regu­la­te the oxy­gen in the SEAWATER Cube with the help of our spe­cial­ly deve­lo­ped flow pumps and the use of tech­ni­cal oxy­gen bet­ween 70 and 100%. The oxy­gen sup­ply is con­trol­led by our auto­ma­ti­on software.

Efficient oxygen supply through Venturi effect

With the help of the SEAWATER flow pump we iuse oxy­gen in a par­ti­cu­lar­ly effi­ci­ent and cost-effec­ti­ve way. We use the Ven­tu­ri effect, in which the water flow is first pum­ped into the nozz­le and then acce­le­ra­ted by a con­s­tric­tion. This crea­tes a nega­ti­ve pres­su­re which can be used to suck in a medi­um (ambi­ent air or oxy­gen) through a sepa­ra­te ope­ning on the nozz­le. The medi­um forms par­ti­cu­lar­ly fine bub­bles when flowing out of the nozz­le, which have a high exit velo­ci­ty and thus tra­vel a long distance in the water. This gives the oxy­gen intro­du­ced a lot of time to dis­sol­ve com­ple­te­ly in the water and thus be avail­ab­le to the fish.

Increase of the well-being of fish by specific current conditions

A side effect of the oxy­gen input by means of flow pumps is the tar­ge­ted flow that can be achie­ved with the ejec­ted water jet of the ven­tu­ri injec­tor. It crea­tes a so-cal­led cir­cu­lar flow in the cohorts, which is slo­west in the midd­le of the tank and fas­test towards the tank edge. Wit­hin the cur­rent, each ani­mal has the pos­si­bi­li­ty to choo­se its favo­ri­te spot. Thus, the cur­rent sup­ports the natu­ral swim­ming beha­vi­or of the animals.

Flow in the holding tank for better water purification

Often the fish also move as a sho­al with the cur­rent through the tank, which makes the water move­ment very fast and tur­bu­lent. This also hel­ps to trans­port all par­ti­cles and excre­ments that collect in the water to our fil­ter tech­no­lo­gy from time to time. This not only saves the plant ope­ra­tor dai­ly working time in clea­ning the tank, but also pre­vents the for­ma­ti­on of bio­films.

With the SEAWATER Cube, we place spe­cial empha­sis on crea­ting opti­mal living and growth con­di­ti­ons for the fish during bree­ding. The use of a flow pump con­tri­bu­tes to this. In addi­ti­on to opti­mal flow con­di­ti­ons and effi­ci­ent oxy­gen input, tech­ni­cal sin­gle-flow pumps pro­mo­te water qua­li­ty in aquacul­tures. We are con­vin­ced that spe­ci­es-appro­pria­te hus­bandry and clear plant water have a very strong impact on the qua­li­ty of the final pro­duct. The­re­fo­re, we are con­stant­ly working on the fur­ther deve­lo­p­ment of our sys­tem and rese­arch in future-ori­en­ted tech­ni­ques to make aquacul­tu­re in clo­sed recir­cu­la­ti­on sys­tems attrac­ti­ve and thus make a sus­tainab­le con­tri­bu­ti­on to the pro­tec­tion of natu­ral stocks.

Refe­ren­zen

http://www.aquarienfische.info/seiten/stroemng.htm, recal­led 23th Janu­a­ry 2020

https://www.umwelt.sachsen.de/umwelt/wasser/1416.htm, recal­led 17th Febru­a­ry 2020

— Pic­tu­re by SEAWATER Cubes