Without seeing your water, I am going to guess that the liquid algaecide you are using is a quat (quatenary ammonium). It is an effective algaecide but it can cause the water to get a little "sudsy" or "foamy". You may have had just a bit too much in there. A way the old service company guys would check your algaecide level was to put their hand in the pool and shake it around. If it foamed some, then you had enough. Usually a good shock will clear that up.
It is easy for soap to get into a swimming pool, because the people who swim in that pool have washed themselves with soap and may not have rinsed all of it off. Soap in pool water then causes bubbles to turn into suds. Anti-sudsing agents are available, although at some point you may just prefer to drain and re-fill the pool.
White suds are usually the sign of a chemical reaction or pollution in the water. So, yes it is possible that it is harmful to the fish.
Suds would not be caused by the generator. Certain algaecides can cause suds, or just conaminates from bathers, in which case an enzyme product will fix that. In some cases very low calcium can cause that.
Soap suds are created when the surface tension of water is decreased by the presence of soap molecules. The soap molecules have hydrophilic (water-attracting) and hydrophobic (water-repelling) ends, which allow them to surround and trap air bubbles within the water, forming suds.
Suds are typically created when water is agitated with soap or detergent. The agitation causes air to become trapped in the solution, forming bubbles that appear as suds. Different types and amounts of soap or detergent, as well as the hardness of the water, can affect the amount of suds produced.
If you like suds.
Suds refer to the bubbles that are formed on top of water, which contains soap. Water that has been infused with soap or any other similar synthetic detergent can create suds.
It means you have algae in the water.
Suds are formed by the agitation of soap and water, which traps air. Suds can go away when the air bubbles pop or when the soap is diluted with more water, breaking down the bubbles. Additionally, using chemicals like vinegar or lemon juice can help break down suds faster.
Suds are typically created by mixing water with soap or detergent. Agitation, such as stirring or shaking the mixture, helps to incorporate air into the solution, leading to the formation of bubbles and suds. Ultimately, it is the surfactant components in the soap or detergent that reduce the surface tension of water, allowing bubbles to form and suds to appear.
Rice with water!
One person suggested:-Try to put salt on the suds... If they are detergent suds try making up a mixture of lightly soapy water. (Soap not detergent)Put it in an atomiser and spray some on the suds, I think the suds will start to self destruct. Detergent and soap don't like each other. Use as little as possible to get the desired effect as I am sure pools don't particularly like soap either!