Undergravel filters (Need advice and your thoughts)

[CHOMPERS]

Note....."clogged" airstones can be unclogged by soaking in a bleach/water solution

Hydrogen Peroxide works really well too. I didn't think it would work as well as bleach but I was really surprised.

 

[tcarswell]

Thanks guys peroxide I never would have thought

 

[CHOMPERS]

So im probably best off with just the airstones then correct?

I can't honestly bash powerheads, but if I were to set up another UGF I would use airstones. I think the power (or lack of power) of the air pump is going to be a big factor in the final output of air through the air stones vs. no air stones. Experiment with both ways to see what is optimum for your pump and air stones. (The white expanded plastic diffusers clog quickly because they have super fine pores.)

 

[dogofwar]

That fish poop and gunk will turn into nitrates isn't a myth.

The same stuff that you siphon out of the gravel (or off of the bottom in a bare bottom tank) is the same stuff that settles (or is sucked) under an undergravel plate...which builds up as nitrates.

Of course, gravel vacuuming and water changes will help, but the hard to remove gunk under and UGF will build up over time and lead to more nitrates...kind of like if you didn't vacuum a portion of the gravel in a tank over the course of months or years.

Actually the nitrate thing is another myth. This is guaranteed by the Conservation Law of Matter. A quick run down is that matter can not be created nor destroyed (nuclear reactions asside). The total nitrates are limited to what is put into the tank.

At the very worst, the UGF delays the release of organics into the nitrogen cycle, but that happens with any filter. This is countered with regular gravel vacs and water changes (nice that they happen at the same time).

The gunk that builds up under the plates is the last in the process of food and poo breaking down or is the last of the organics that takes forever (bone meal for instance). The bulk of the nitrogen products have already been removed from the organics before they reach the bottom of the plates. When the gunk continues to break down, it becomes dissolved in the water (dissolved organics) and is removed at the next water change. Any nitrogen products entering the nitrogen cycle from the gunk at this point is very minimal in comparison to the fish urine, fresh poo, and rotting food.

 

[spiff]

That fish poop and gunk will turn into nitrates isn't a myth.

The same stuff that you siphon out of the gravel (or off of the bottom in a bare bottom tank) is the same stuff that settles (or is sucked) under an undergravel plate...which builds up as nitrates.

Of course, gravel vacuuming and water changes will help, but the hard to remove gunk under and UGF will build up over time and lead to more nitrates...kind of like if you didn't vacuum a portion of the gravel in a tank over the course of months or years.

What Chompers says on that does make sense. Basically, any matter that makes it to the bottom has already been thoroughly broken down because it took so long to get there. Its not to say that it still won't contribute to readings, but its probably negligable. The myth probably is based on fact though too, but probably early in the hobby when there was a higher rate of neglect due to ignorance and finding tanks with two inches of sludge was common. Today for someone to be that ignorant is sheer neglect.

 

[dogofwar]

So explain the magical transformation that occurs between poop, food, etc. falling into the gravel and (the air or powerheads) sucking it under the under gravel plate....that results in the stuff being converted into something that is totally non-organic (i.e. doesn't contribute to the nitrogen cycle).

The stuff that gets sucked under the plate is the stuff that I clean off the bottom of my bare bottom tanks...and definitely is organic waste.

 

[tcarswell]

So explain the magical transformation that occurs between poop, food, etc. falling into the gravel and (the air or powerheads) sucking it under the under gravel plate....that results in the stuff being converted into something that is totally non-organic (i.e. doesn't contribute to the nitrogen cycle).

The stuff that gets sucked under the plate is the stuff that I clean off the bottom of my bare bottom tanks...and definitely is organic waste.

Now im confused

 

[Bderick67]

So explain the magical transformation that occurs between poop, food, etc. falling into the gravel and (the air or powerheads) sucking it under the under gravel plate....that results in the stuff being converted into something that is totally non-organic (i.e. doesn't contribute to the nitrogen cycle).

The stuff that gets sucked under the plate is the stuff that I clean off the bottom of my bare bottom tanks...and definitely is organic waste.

It's called mineralization. Organic matter is broke down into variuos inorganic minerals. Trying to find a HarleyK post on this.

Once the nitrates are in the water column they are removed though water changes this is the same principle other filters work on. Trap the mechanicle waste, as it breaks down consume the ammonia, nitrite, remove nitrates with water changes.

 

[dogofwar]

So in a UGF what's trapping physical waste? The gravel.

UGFs work by sucking stuff through the gravel and under the plate...which is the problem with them (mechanical waste gets trapped under the grate). It's no different than never cleaning a HOB or canister filter....or having a big hunk of poop in your tank.

Poop doesn't get "mineralized"...if your tank is cycled (has sufficient nitrifying bacteria), it gets broken down into nitrate...which can be dilluted with water changes...but doesn't remove the source of the nitrate.

 

[thor meeki]

For the money UGF are the shiz.
I had used an UGF for years, & it did it's job well . There is a bit more work w/ one but if your on a buget it's worth it. I would say if you can afford a canister, sump, ect. cleaning time would be faster, easier. As far as power heads vs air I've used both. I like air the best. My power heads from time to time would suck little rocks into the impellers & stop them PITA!
I recently upgraded my filters in the 55gal. Did away w/ the UGF & replaced it w/ a fluval405. I still have my trusty magnum350 running as well. I'm happer w/ this set up & it's alot less of an eye sore.