question about drilling siphon hole in return plumbing

Cox · 04/19/2006, 02:13 PM

I have a return made of 3/4" PVC 90 degree elbows that I'm about to install. How big should the siphon hole be? I also understand that this hole should be just below the water surface, correct? Also, pardon my ignorant questions, but wouldn't water shoot out of the siphon hole at a high force since it's smaller than the 3/4" outlet?

hmott · 04/19/2006, 02:40 PM

yes your right.. and yes it will.

Its below the water, so water shooting out it isn't a big deal, its also a small hole so not much gets out it. I suggest you do two holes, one on each side. So if one gets clogged you still have a second backup, maybe even have it a little lower than the first if you want them on the same side. Then if a snail is over one, or algae has clogged it your still ok. Just be sure and test that your sump can hold the water from the lowest hole when you test, incase that top one gets clogged.

Hobster · 04/19/2006, 02:42 PM

Yes it should be a little below the water line. I have used about a 1/8 " hole. Put 2 in case one gets clogged or a snail is sitting on it.

Water will come out of it, but most of the volume will be through the larger hole so it doesn't really shoot out of the smaller hole.

Hobster · 04/19/2006, 02:44 PM

yep, what hmott said.

Cox · 04/21/2006, 03:57 PM

Thanks, y'all.

04/19/2006, 02:13 PM	#1
Cox Registered Member Join Date: Jul 2005 Location: Maryland Posts: 128	question about drilling siphon hole in return plumbing I have a return made of 3/4" PVC 90 degree elbows that I'm about to install. How big should the siphon hole be? I also understand that this hole should be just below the water surface, correct? Also, pardon my ignorant questions, but wouldn't water shoot out of the siphon hole at a high force since it's smaller than the 3/4" outlet?

04/19/2006, 02:42 PM	#3
Hobster Registered Member Join Date: Nov 2003 Location: SW Florida Posts: 2,444	Yes it should be a little below the water line. I have used about a 1/8 " hole. Put 2 in case one gets clogged or a snail is sitting on it. Water will come out of it, but most of the volume will be through the larger hole so it doesn't really shoot out of the smaller hole. __________________ "You call someplace paradise, kiss it goodbye" The Last Resort, The Eagles Current Tank Info: Downsized, took down the 75 g SPS and going with a 20L and 10g softy nanos.

04/19/2006, 02:44 PM	#4
Hobster Registered Member Join Date: Nov 2003 Location: SW Florida Posts: 2,444	yep, what hmott said. __________________ "You call someplace paradise, kiss it goodbye" The Last Resort, The Eagles Current Tank Info: Downsized, took down the 75 g SPS and going with a 20L and 10g softy nanos.

04/19/2006, 02:40 PM	#2
hmott Registered Member Join Date: Apr 2004 Location: Belpre Ohio Posts: 470	yes your right.. and yes it will. Its below the water, so water shooting out it isn't a big deal, its also a small hole so not much gets out it. I suggest you do two holes, one on each side. So if one gets clogged you still have a second backup, maybe even have it a little lower than the first if you want them on the same side. Then if a snail is over one, or algae has clogged it your still ok. Just be sure and test that your sump can hold the water from the lowest hole when you test, incase that top one gets clogged.

04/21/2006, 03:57 PM	#5
Cox Registered Member Join Date: Jul 2005 Location: Maryland Posts: 128	Thanks, y'all.