Take the end cap off. It has such a tiny hole it will clog and in worst case, shoot jet streams if there is pressure being built up. I stop using the redsea clip as well. Some liquid won’t be a problem but some thick or mixed liquid such as kalk will build up.
Its pretty common even with an open 1/4" tube. The last bit that has not been dosed usually dries out and it just builds up. I try to submerge the alk dosing tube for that reason.
If it happens you can soak the end in hot water and poke it with a tooth pic to clean it out.
Also make sure other dosing drips do not splash or otherwise wet the end of the alk line. I have seen that other dosing agents accelerate the calcification at the tip of the alk line. Or vinegar, protein, or part b can cause the tip to calcify