piranhaking
New member
What are some of the advantages/disadvantages to using ugf's and are they really as bad to cause nitrate issues as many people say?
Under gravel filter?
- Thread starter piranhaking
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Petstorejunkie
New member
under gravel filters are great if you use them in reverse. i like to route the return water through them so i never have to vaccum the gravel, it ensures that all yuckies get picked up by the filter.
If under gravel filters are used as origionally intended they can cause huge nitrate issues. i always give people the analogy of a child cleaning their room. you ask a teenager to clean their room, and what do they do, shove it all into the closet. essentially, did the mess really go away, or is it now hidden and harder to get to? this is what an under gravel filter does to all of the fish waste, it puts it in the hardest place to reach in the entire tank!
If under gravel filters are used as origionally intended they can cause huge nitrate issues. i always give people the analogy of a child cleaning their room. you ask a teenager to clean their room, and what do they do, shove it all into the closet. essentially, did the mess really go away, or is it now hidden and harder to get to? this is what an under gravel filter does to all of the fish waste, it puts it in the hardest place to reach in the entire tank!
tntechworker
New member
wouldnt an rfugf be rather unefficient with a very small grain size of sand? and wouldnt it also prevent the sand from being able to remove nitrate?
Fast Fred
New member
Sand won't work with a RFUGF unless your use window screen between the two. You sand won't remove nitrate unless it is a Deep Sand Bed of at least 4". It which case any UGF will not allow denitrification, no matter how deep the sand is. Denitrification occurs from Non-aerobic bactreria, meaning no oxygenated water passing through it.
piranhaking
New member
id like input on this from as many people as i can get even if you agree with what has already been said
Toddrtrex
Premium Member
Paul B
Premium Member
That link in the last post is about my tank. UGFs get a bad rap because people try to use them the way we did on fresh water 40 years ago, in salt water you should not use them like that. Mine has been running for 35 years with only one cleaning after 25 years. The difference is that I run it in reverse very slow (150 gal/hr down each tube) and you must put a sponge filter on the intake of the powerheads. There is very little maintenance except that you should stir up the gravel (you can't use sand) a few times a year and suck out the detritus with a canister or diatom filter. You should "powerwash" the rocks in any reef anyway so while you are doing that you can stir the gravel.
If you run it slow you will eventually also have no nitrates.
Good luck.
Paul
If you run it slow you will eventually also have no nitrates.
Good luck.
Paul
