Opinions appreciated: check valve vs anti-siphon holes in overflow returns
 

I am looking for input from seasoned users who have either check valves or drilled return lines.

I have read, and read, and read, for 5 months online. I've seen horror stories about check valves failing. I've also seen the same said about drilled holes due to snails and such.

I have flow-tested my system, and am happy with it so far, but would like the option of placing my 3/4" loc-line nozzles either below the surface or just skimming.

I guess that there is danger either way. Blockages being the prime concern.
Personally, locline just below the surface is my choice.

No offence, but you're not giving me a long-time user experience with your reply.
I'm looking for user responses with long-time experience.

Should I use a union check valve or not?
I don't want to drill my lines.
What's your experience?

I've been using a check valve for a year and a half, no issues.

How do you know how long this person has been in fish keeping.

I guess I won't offer advice.

Just removed the union check valve yesterday and run the nozzle just below water surface. Reason for removing is every time I turn off and on the pump it making stupid noise.

I drilled 2 small holes just below the waterline on each of my locklines, have had no probs for over 2 years, cleaned them @ a month ago and all holes were still flowing.

lol dont you know? online post counts are obviously an accurate representation of how much experience you have

I use both.....my check valve is on a union and I have two.....I swap them out very so often for cleaning....