Sturgeon & Sterlet
How to keep
in the pond
Sturgeon fish belonging to the family Acipenseridae which are an ancient species of bony fish that developed many millions of years ago and are found exclusively in the northern hemisphere. There are over twenty different species and several hybrids too, with Sterlets being the most popular seen for sale as they grow slightly smaller.
The Sterlet is a poyamodromous species (freshwater only) and native to eastern Europe and western Asia.
In The Pond
When buying Sturgeon species for the pond we have to take several things into account.
These fish originate from rivers such as Volga and Danube which are by nature cold and highly oxygenated. Therefore, it is of utmost importance that we maintain a high dissolved oxygen content at all times for these fish in our pond with levels not being allowed to drop below 6mg per litre.
There are many things within the pond which consumes oxygen, and the warmer the water then the less dissolved oxygen it can hold. Adding an air pump and generally moving the water from fountains and waterfalls will all help to put oxygen into the water, but even then we highly recommend to use a reliable test kit and measure your ponds oxygen content on a regular basis.
Another water parameter to measure is the pH. Sturgeon require slightly alkaline water so a pH of 7.0 - 8.2 is good for them. Regularly check the KH content of the water as this is responsible for buffering and maintaining steady pH levels.
Naturally, ammonia and nitrite levels should be zero and the correct size and well maintained biological filter will achieve this. Water temperatures should be somewhere between 4 degrees centigrade and no more than 25 degrees centigrade.
The other thing to take into account when considering Sturgeon for the pond is their size. They are often seen for sale at a few inches in length, but these fish grow large and expect a metre or more even for "smaller" species, including Sterlets.
The actual minimum size of pond required will depend on its shape and depth, but as a guide we suggest at least 1,500 gallons (6,800 litres). Koi ponds also need to be relatively large and it is often observed that Koi are often kept together with Sturgeon for this reason.
Even a large domestic aquarium is totally unsuitable for any of these fish.
Even small Sterlets will need to grow to a metre or more and will suffer in small ponds.
ClearWaters KH Booster rapidly raises the carbonate hardness which is responsible for steady pH levels and effective biological filtration.
Click in the product for more information about KH.
The downward facing mouth and "feelers" are a sure sign that these fish will search for food from the pond bottom.
Sinking food from Nishikoi is produced primarily with Sturgeon in mind. Click on the food jars for more information.
The Sturgeon keeper needs to be aware that many pond treatments available off the shelf are deadly to these fish.
Parasite remedies containing any Formalin / formaldehyde are to be avoided and also those containing Potassium permanganate.
Some anti parasite treatments and also those for treating green water or blanket weed algae contain copper sulphate which is highly toxic to the Sturgeon fish.
It is very important however to remove blanket weed (string algae) from the pond. Sturgeon are a bony fish and they can swim into the dense growth of blanket weed which leads to their spines anchoring onto the weed making it impossible for them to escape, leading to its death.
A reliable manufacturer of algae treatments will show the additives within the product. However, be aware that many algae treatments state that the product uses "natural minerals" but copper sulphate is a natural mineral!
When adding any treatment or medication to the pond, there will be a drop in dissolved oxygen levels. This is particularly so when using an algae treatment due to the increased biological demand created by the dying algae.
Always remove dead and decaying vegetation from the pond after treating and remove silt or detritus from the pond bottom and always monitor dissolved oxygen levels with a reliable test kit.
Regardless of common belief, Sturgeons do not eat blanket weed algae or "clean the pond bottom", but will look for food such as worms, crustaceans and insect larvae.
In the ornamental pond it is recommended to feed a sinking pellet food high in protein. In the summer months, these fish require 2-3% of their body weight of good quality food per day in the summer, which contains at least 40% digestible protein. And, although they require less in the winter it is important to feed these fish all year round, albeit less than in the summer months, Sturgeons will continue to eat down to a water temperature of 4 degrees centigrade.
Sturgeon are naturally a slow fish and their eyesight is not as good as other pond fish. It is therefore important that you feed the other pond fish first to prevent them from eating all the Sturgeon food before those fish have time to eat it. These fish need time to find the food on the pond bottom and swim over it using their feelers which hang from their top lip. There is no problem however to the other fish within the pond should they eat some of the Sturgeon food.
One of the most popular reasons of Sturgeon suffering from a premature death is from malnutrition which makes observing that these fish receive sufficient quality food an important part of their wellbeing.
Just as with any other fish food, remove any uneaten food from the pond after 15 minutes of feeding and adjust quantities for the next feed time.
ClearWaters Blanket Weed Treatment contains neither copper or zinc and is safe to use with all pond fish including Sturgeon species.
Click on the product picture for more information.
The spines on Sturgeon makes them susceptible to becoming tangled in filament algae and resulting in their death.