When i first started i fished only a little while before immediatly buying the next level in farming tech so they switched to coconuts and the ocean never got algee soon after the dam was built and they all switched to crops still no algee in the ocean i got after awhile i got 90000 and spent it on level 3 farming and i found the algee eating fish and put 7 in the ocean will i still get the puzzle even though the ocean has no algee?

If there's no algae, why don't you keep fishing the ocean until it appears? Then start stocking up on algae-eating fish?

its to difficult to keep draging them to the ocean when they directly go back to farming

You only need to drag them in a few times, and they'll start doing it on their own.