Antichlor

Dosage: 1 ml of antichlor per ml of sodium hypochlorite dosed. After addition, shake to mix better and allow to act for at least 4 hours before adding fertilizer and starter culture.

Sterilization of seawater

Especially for the cultivation of sensitive phytoplankton species such as Isochrysis or Rhodomonas, the salt water used should be sterilized beforehand.

For this we use the chemical sodium hypochlorite. This is contained in chlorine-containing cleaning products, for example, which you can easily buy in the supermarket. When buying, please make sure that it does not contain any surfactants or other additives. The branded product DanKlorix©, for example, contains no other additives apart from sodium hypochlorite and can therefore be used without hesitation. Warning: When handling such chemicals or cleaning products, we strongly recommend that you wear gloves and safety goggles! You should also make sure that the room in which you are working is well ventilated. And please remember to protect your clothing, because chlorine is a very effective bleaching agent and creates unsightly stains when it comes into contact with colored textiles.

Depending on the contamination of the source water, you should use between 0.5 and 5 ml of chlorine cleaner per liter of salt water. We usually add 0.75 to 1 ml of chlorine cleaner to our medium, as the (germ) contamination of tap water in Germany is very low and it is best to use osmosis water to prepare the salt water anyway. We only add fertilizer to the salt water after sterilization with sodium hypochlorite so that vitamins, for example, are not damaged by oxidation. Theoretically, the sterilization of the medium is complete after about 30 minutes. However, it is recommended that you leave the mixture to stand for 12 hours or, ideally, overnight.

Before the phytoplankton fertilizer and starter culture can be added, the chlorine must be completely neutralized. This is where antichlor comes in. For every ml of the chlorine cleaner used previously, add one ml of the antichlor solution.

4 hours after adding antichlor, all of the chlorine should have been converted to harmless hydrogen sulfate. This can easily be checked using chlorine test strips. If you don't have chlorine test strips to hand, your nose will do - it is very sensitive to chlorine.