I have seen on the safety sheets of common swedish brands of bleach that they often contain "kaliumsilikat" or "natriummetasilikat" (don´t know the english term, but I think it is also commonly used in washing powder).
What effect do you think this could have in a pool?

Here we have powdered products called Washing Soda or Soda Ash and they raise PH/TA. Not sure if they are the same.....

I did find one website that equated/translated "kaliumsilikat" to "Potassium Silicat", whatever that is...

Can you just find sodium hypochlorite?

The bleach I refer to contains 5% sodium hypochlorite, that´s the main ingredients. These other "silikats" are of less %, but still I wonder if they would be harmful for the pool.
I have not found any other source of sodium hypochlorite right now.

Someone should find a translation if they can. This sounds like calcium silicate though could be sulfate and the other could be sodium. Normally, bleach and chlorinating liquid have a small amount of excess lye which is sodium hydroxide so maybe that's the translation.

No, it is not lye. (Lye is a common third ingredient)
It translates to SodiumSilicate or PotassiumSilicate, also known as water glass. Chemical formula something like this:
Na2[SiO2(OH2)] · 4 H2O or Na2SiO3. It is apparantly a common ingredient in bleach.

I'm not sure why it's so common in bleaches since the normal chlor-alkali process shouldn't be including it since chlorine gas is added to lye to make bleach. Perhaps it's an impurity in the lye or in your country the manufacturers are intentionally adding it (though I don't know why). At any rate, it's not a problem in pools. The only thing the silicate does is slightly raise the pH, but far, far less than the lye so essentially it's negligible.

Perhaps it is added as a thickening agent? Silicates are sometimes used with oxygen bleaches as a stabilizer but this is NOT the type of bleach we are talking about. The kind of bleach we are referring to is, I believe, called natriumhypoklorid in your language and it is sodium hypochlorite in English.
Not hard to figure out that natrium is sodium (Na) and kalium is potassium (K) and silikat is silcate.

EDIT: a bit of reseach indicated that silicates are sometimes added to bleach formulation to buffer the pH. Not quite sure of the chemistry behind it since I could not find much info.