Undergravel filtration?

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Musket

Aquarium Advice FINatic
Joined
Feb 18, 2006
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I have a new 46g bow and wasn't sure how to set up filtration. I have an Aqua Clear 70 (for 40-70g tank) seeding on my 10 gallon (yes set to low and hitting into a rock so as not to disturb the inhabitants too much- so far they do not seem to mind the extra flow).

I was also wondering about an undergravel filter. All my smaller tanks have one, and one that is moderate to heavily planted is doing well. Each also has an HOB + an internal filter of some sort.

One says it's up to you - oh thanks, that helped a bunch.
One says it pulls the uneaten food and debris into the gravel to decompose rather than remove it from the tank.
One says if you are having a planted tank you absolutely need an UGF to feed the roots with the uneaten food and debris that is pulled into the gravel.

I have only one tank that does not have an UGF, my 5g bow that sits on my desk.
How often and how DEEP do I clean the gravel without an UGF?
Your opinions and suggestions on this?

Thanks so much. All suggestions will help in determination of how to set up this new beauty.
 
I had a UGF in my 55 Gal . . .when my XP2 came in the mail . . .I removed it . . .there was some disgusting stuff under there. I won't be going the UGF route again, in any size tank.
 
One says it's up to you - oh thanks, that helped a bunch.

That would be me. And it's true. You know the pros and cons, so you are the only person who can make the decision. Not trying to be rude, but that is the truth. :)

Without proper maintence, they can be a hassle. You would need to make sure to perform regular water changes to prevent buildup under the UGF. Things can sit down there and cause nitrate problems. With regular maintence, including syphoning under the UGF, you may not have these problems.

If you do proper cleaning on your planted tank, the roots do not need a UGF to survive. And, heavily rooted plants should not be put with an UGF, because they can grow below the UGF and not get the required nutrients from the water. A UGF is a no in a planted tank, IMHO, but it can be done if you really wanted a UGF and with the proper plants.
How often and how DEEP do I clean the gravel without an UGF?

Just as deep as with an undergravel filter, and every two weeks or so. I vaccum all the way down to the bottom.
 
I agree with DT. UGFs and plants do not mix. I have always been told never to use one when planting a tank. Plus, they are not as efficient as a hob or canister. The debris that gets trapped under the plates causes them to be nitrate factories (unless properly maintained, which can be a pain).
 
Well you just vacuum the gravel deep. From what was said above you do that without UGF too. However, how to you keep the oxygen flow thru the gravel without the filter? Or do the lant roots help with that?
 
I have UG filters on most of my tanks. I either run an AquaClear intake into a lift tube, or run powerheads modified for reverse-flow into the lift tube. The two tanks with powerheads/reverse flow are set up with a layer of blue&white bulk filter material between the plate/s (PennPlax Undertows, the only UG filters I use) and the gravel bed. The result is a much thinner layer of gravel, with the water flowing UP, pushing dirt out, not in. Very easy to siphon clean. Also, much more surface area for bio-filtration than a much deeper gravel bed. The powerheads are prefiltered with Quickfilter cartridges, though I use more of the bulk filter material instead of the pads supplied with the Quickfilters. The pads are great for clearing fine particles, but clog too quickly for long-tern use.
The other two tanks, run with oversized Aquaclear filters, (2 500's on the 55, one for each plate, and a 70 on the 38) have minimal debris accumulation in the gravel. The area under the plate/s stays clear; whatever makes its way through the gravel is caught in the sponge blocks.
 
I am not a fan of UGF's. I took one out of an established goldfish tank because the nitrates would never get below 40 ppm no matter how many water changes I did. When I took the UGF out I found out why. The stuff under the plates was to put it straight forward, GROSS. Decaying food and feces, it was terrible. Since I got rid of the UGF the nitrates go between 20-40 ppm between changes. There is a high bioload in that tank so that is normal. I don't and haven't ever kept plants with a UGF so can't comment.
 
A couple of things need to be cleared up about UGFs. They are not nitrate factories, any more than any other type of filter. The amount of nitrate that will be produced in a tank is related to the bioload in that tank. UGFs cannot create nitrate. They do have some drawbacks, and it is believed now, that they are detrimental to plant growth. This is contrary to what was once believed, that being that they were essential. As far as maintenace goes, aside from regular gravel vacuuming, a siphon tube can be inserted into the lift tubes and quickly removes any accumulated detritus from beneath the plates. If a reverse flow power head with a prefilter is used, there is nothing under the plates or in the gravel. The upward flow through the gravel will keep detritus at the surface where it is easily removed by siphon or filtration. I presently have 2 tanks using UGFs, one of which has been setup for 12 years. While I wouldn't necessarily recommend them, I see a lot of misinformation about them, being spread as gospel, when in fact it is not true. The most obvious one being that they are "nitrate factories". Any good, functioning filter is a nitrate factory.
 
The reason why I called them "nitrate factories" is because people generally do not maintain them properly (as I stated). When they are not maintained properly, the debris sits under the plates and causes higher nitrates.
 
I would think you would have to pull them out weekly to keep any amount of debris from building up underneath them. I know a few individuals who attach power heads to one of the towers to suck the debris out but, no thank you. I had UGF's on my two 10's and on my 20. After I removed them it much less work to keep the tank clean with gravel vacs and PWC's. UGF's are just too much work IMHO.

Oh, and I'm FINALLY have success with live plants in my 44... I "potted" them. I put them in clay pots with the gravel substrate and they are growing like crazy without causing any nitrate spikes when I test. I only have three pots in there though... I imagine if you had a lot, it would cause an increase in nitrates since I don't gravel vac the pots.
 
Yes. I do believe it has been well stated that they CAN cause issues WITHOUT proper maintenence. If you want to fool around with vaccuming under them and such, go for it. If you want to not bother and go with an HOB style filter, that's fine too. Once again, the choice is up to you, Musket. :)
 
Undergravel Filtration?

toddnbecka
The result is a much thinner layer of gravel, with the water flowing UP, pushing dirt out, not in. Very easy to siphon clean. Also, much more surface area for bio-filtration than a much deeper gravel bed.

Why would a thinner layer of gravel give a better surface area for bio-filtration?
How do you make the powerhead a reverse flow? Or do you have to purchase it this way or a conversion kit?

The two tanks with powerheads/reverse flow are set up with a layer of blue&white bulk filter material between the plate/s (and the gravel bed.

How do you clean this filter? Wouldn't that be difficult? Is it necessary? Wouldn't the plant roots grow thru it? Would that be alright, Ideal? (Except you would damage the plant if you had to change the pad.)

The powerheads are prefiltered with Quickfilter cartridges, though I use more of the bulk filter material instead of the pads supplied with the Quickfilters.
I've never seen or heard of this, can you explain? If the powerfilters are pushing air down the lift tube so that the air rises up thru the gravel, why do you need a prefilter? Because instead of the powerhead flowing water into the tank, it is sucking it from the tank? Where does the prefilter go. Do you have a picture of the setup? Obviously I am new to this concept.

The other two tanks, run with oversized Aquaclear filters, (2 500's on the 55, one for each plate, and a 70 on the 3Cool have minimal debris accumulation in the gravel. The area under the plate/s stays clear; whatever makes its way through the gravel is caught in the sponge blocks.
Does this mean 3 filters? One filter intake tube inside each lift tube?
Do you mean the sponge blocks inside the AC500?

Which of the 2 methods seems to work better? Do you still vacuum in both setups? (I imagine you would) Do you have plants in either of these tanks? Which setup? What kind of plants, how are they doing? Thanks


BillD
If a reverse flow power head with a prefilter is used, there is nothing under the plates or in the gravel. The upward flow through the gravel will keep detritus at the surface where it is easily removed by siphon or filtration. I presently have 2 tanks using UGFs, one of which has been setup for 12 years. While I wouldn't necessarily recommend them
I can see how the reverse flow would make it easier to vacuum.
Why are you not recommending them?
Is your UGF setup with a reverse flow?
The one that has been setup for 12 yrs, How is that one setup?
Do your tanks have plants? How are the plants doing with this type setup?


Devilishturtles
but it can be done if you really wanted a UGF and with the proper plants.
Could you give me a list or description of the "right plants". KNowing what plants I can and cannot successfully keep with a UGF might help in my (and others reading in the future) decision.

Thank you everyone so far, this is exactly the type of information I was looking for, pros and cons for of all types of ways to use the UGF. This thread will help others in the future (as long as it can be found) :)

Anyone else with experience in these types of setups? Or other types?
 
Why would a thinner layer of gravel give a better surface area for bio-filtration?

The filter media layer provides the surface area, it has much more surface area than a thicker bed of gravel.

How do you make the powerhead a reverse flow? Or do you have to purchase it this way or a conversion kit?

Penguin powerheads have a reverse-flow adapter kit available. I use Aquaclears, so I used pvc elbows over the outflow tube and large-diameter vinyl tubing ti fit into the lift tube. Aquaclears have a reverse-flow option built into them, but using that reduces water flow considerably compared to running them the normal way.
How do you clean this filter? Wouldn't that be difficult? Is it necessary? Wouldn't the plant roots grow thru it? Would that be alright, Ideal? (Except you would damage the plant if you had to change the pad.)

The filter pad gets siphoned along with the gravel, though very little actually collects in the pad. UG filters aren't generally used in planted tanks. The plants in those tanks are plastic.

[/quote] If the powerfilters are pushing air down the lift tube so that the air rises up thru the gravel, why do you need a prefilter?
The powerheads are pushing water, not air, through the lift tubes. The prefilters are to keep fish from being caught in the intake/impeller. They also support the weight of the powerhead.
and a 70 on the 3
Oops, should read: a 70 on the 30. That tank has 1 plate, with a powerhead on one tube, and an Aquaclear 300 on another.

[/quote]One filter intake tube inside each lift tube?
Do you mean the sponge blocks inside the AC500?
Yes
 
Re: Undergravel Filtration?

Musket said:
Devilishturtles
but it can be done if you really wanted a UGF and with the proper plants.
Could you give me a list or description of the "right plants". KNowing what plants I can and cannot successfully keep with a UGF might help in my (and others reading in the future) decision.

Musket, you'd need plants with very little or no root system. Floating plants, or plants that can be attached to the rocks. Java Fern/Moss, Anubias, Anarachis, etc.

Also, I am attaching a link about UGF's and planted tanks that will give you a general overview.

http://www.aquariaplants.com/undergravelfilters.htm

HTH
 
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