Sterlet and Sturgeon are very popular because of their prehistoric, shark-like looks and the way they stick their noses out of the pond water.

But there are a few things you need to know about them before you add one to your pond. 

How big do Sterlet and Sturgeon grow?

Most Sterlet grow to 36”/90cm in length, but Sturgeon species can grow a lot bigger and pond owners have achieved lengths of five feet or more with Diamond sturgeon. Sturgeons are some of the biggest fish in the world and the largest ever Beluga Sturgeon (of Caviar fame,) was 24ft long and weighed over 3000lbs. The species we keep are much smaller but still capable of growing to be the biggest pond fish you can keep. Bigger even than the biggest koi carp. 

What size pond do Sterlet and Sturgeon need? 

A 3’ sturgeon or Sterlet would need a minimum pond size of 18’x12’x3’ deep, and they are active swimmers that will spend all day swimming the length of the pond and back again. A huge circular pond would be good for them as they can swim around the outside without having to stop and double back. Large ponds are a must.

What filtration do Sterlet and Sturgeon need?

Sturgeon eat protein-rich sinking pellets, cockle, muscles and prawns, sturgeon food pellets and produce ammonia rich waste. Filtration must be top notch to ensure the water is clean and free of debris, and effectively converting ammonia into less harmful substances. Use a combination of mechanical and biological filtration on a large solids handling pump or a gravity system with bottom drain and external pump. A moving bed biological filter and drum filter in combination would work well. 

Use a pond air pump and air stones too to provide high oxygen levels. Even extra pond pumps to provide strong water flow.

Can Sterlet and Sturgeon be kept with other fish species?

They can and are very well behaved, but they are sensitive to some medications so if you keep them with prized koi and need to treat the koi, you may need to remove the sturgeon for the duration. You need to make sure they get the correct food too and don’t get out-competed by other ravenous fish swimming above them. 

Can Sturgeon and Sterlet be kept in the same way as other fish?

Whereas carp, tench and wild goldfish naturally inhabit still, muddy waters full of plant life, Sturgeon inhabit large, cool, fast flowing salmon rivers so come from a different environment. They need a large open space that stays cool year round, has high flow and high dissolved oxygen levels, just like a river. Their spiky, inflexible bodies can get them trapped in dense oxygenating plants and blanket weed and they often succumb in shallow, warm, still ponds with low oxygen levels caused by hot weather.

A large koi pond with rounded edges and a smooth fibreglass bottom would be best for them. They’re not recommended for average garden ponds with lots of plants and shallow depth. 

Can I have more than one Sturgeon or Sterlet?

Yes, you can keep sterlet together or a mix of different species of Sterlet and Sturgeon. They can all be kept the same way, and fed the same food, but a group of them would need a huge pond long term and massive filtration to cope.