undergravel filtration question
- Thread starter maxman
- Start date
You guys are Wacky!!:raspberry:
OK when you are talking about oxygen levels you have to be clear. In air there can be a much higher abundance of oxygen than in water. In water you can have much higher concentrations of oxygen because the saturation level is much lower. Water can be very easily saturated with oxygen leaving much more available to be consumed or dissipated into the atmosphere.
Debris will build up at a rate equal to its deposition. So it will build up in a tank at a constant rate. If in the water column was static it would always be evident. The water column is always being effected by everything in the tank. Nothing will beat a UGF/RUGF for bio filtration capabilities. Nothing will breakdown Nitrogen faster except a fantastic fuge or big wet dry system. I consider many plants to be an integral component of this system of bio filtration and have about 70 in my tank now.
I also believe that you must use more than 1 filter. I always use a UGF, RUGF, or Sponge filter combined with a HOB filter. I count on mulm being pushed through my water column to feed my plants in the tank and outside of the tank. Any excess will be taken up by the HOB filter.
I also believe that you should aim for at least a 100% w/c schedule weekly. I do 3 - 7 33% w/c weekly.
On a different note I also believe I can run a tank without any conventional filtration or water changes infinitely only filling water lost to evaporation.
OK when you are talking about oxygen levels you have to be clear. In air there can be a much higher abundance of oxygen than in water. In water you can have much higher concentrations of oxygen because the saturation level is much lower. Water can be very easily saturated with oxygen leaving much more available to be consumed or dissipated into the atmosphere.
Debris will build up at a rate equal to its deposition. So it will build up in a tank at a constant rate. If in the water column was static it would always be evident. The water column is always being effected by everything in the tank. Nothing will beat a UGF/RUGF for bio filtration capabilities. Nothing will breakdown Nitrogen faster except a fantastic fuge or big wet dry system. I consider many plants to be an integral component of this system of bio filtration and have about 70 in my tank now.
I also believe that you must use more than 1 filter. I always use a UGF, RUGF, or Sponge filter combined with a HOB filter. I count on mulm being pushed through my water column to feed my plants in the tank and outside of the tank. Any excess will be taken up by the HOB filter.
I also believe that you should aim for at least a 100% w/c schedule weekly. I do 3 - 7 33% w/c weekly.
On a different note I also believe I can run a tank without any conventional filtration or water changes infinitely only filling water lost to evaporation.
oops i had an error there.
"In water you can have much higher concentrations of oxygen because the saturation level is much lower. Water can be very easily saturated with oxygen leaving much more available to be consumed or dissipated into the atmosphere."
After i thought about it you cant have a higher concentration of oxygen in water than in air especially at higher temps. So the concentration is lower. But you can saturate it much easier especially at higher temps. This will typically cause the water to lose more oxygen.
I am studying for an exam on Electron Microscopy and im losing it.
"In water you can have much higher concentrations of oxygen because the saturation level is much lower. Water can be very easily saturated with oxygen leaving much more available to be consumed or dissipated into the atmosphere."
After i thought about it you cant have a higher concentration of oxygen in water than in air especially at higher temps. So the concentration is lower. But you can saturate it much easier especially at higher temps. This will typically cause the water to lose more oxygen.
I am studying for an exam on Electron Microscopy and im losing it.
Yes, debris will build up at the same rate, I said that. It is dealing with problems later and dealing with that build up that make other filters better.
And any filter that has a full load of bacteria for the bioload (as in: as long as the tank is cycled) will deal with wastes just as quickly as long as you have the water flow to get the wastes to the media. There are problems with UGF discussed earlier in this thread, such as uneven water flow through the gravel, areas being blocked off with debris, etc. If the nitrifying bacteria are submerged and need an area of x to colonize, then having an area of 4x is not going to help. As said, once you have all you need (the tank is cycled), you aren't going to get anymore.
You guys have your experiences and opinions about UGFs, I have mine. Obviously they differ. Luckily we are on a forum where we all get to share and defend our experiences and opinions and let others decide which makes more sense to them.
And any filter that has a full load of bacteria for the bioload (as in: as long as the tank is cycled) will deal with wastes just as quickly as long as you have the water flow to get the wastes to the media. There are problems with UGF discussed earlier in this thread, such as uneven water flow through the gravel, areas being blocked off with debris, etc. If the nitrifying bacteria are submerged and need an area of x to colonize, then having an area of 4x is not going to help. As said, once you have all you need (the tank is cycled), you aren't going to get anymore.
You guys have your experiences and opinions about UGFs, I have mine. Obviously they differ. Luckily we are on a forum where we all get to share and defend our experiences and opinions and let others decide which makes more sense to them.
kj5kb
KEEPER OF CATS, FISH AND CATFISHES
Did I miss something? The original post was by maxman and appears to have gone off on a tangent...
OK...to address maxman's original question:
In my opinion and with a couple years of experience since I got back into the hobby :grinyes: ...
Do your plates connect together such that water flows under the whole area? Many UGF plates can have 'knockout' areas so that water can move freely from plate-to-plate...or you can modify them to be that way. ( you may need to ty-wrap or superglue them together to keep gravel from falling thru.)
In that case, you only need one powerhead, near the center, not the ends. I suggest a penguin 660r powerhead + an HOB filter, whisper 20 to 40 size or whatever brand you like. If your plates wont flow as one unit, then go with 2 powerheads.
A reverse flow undergravel filter (RUGF) is when you use a powerhead (or canister) to push water down the tube and back up thru the gravel. It improves your biofilter without a lot of the drawbacks associated with the 'original' UGF design. Downflow "normal" original UGFs sucked crud down thru the gravel, and a lot of it ended up trapped under the plates; while RUGFs push the crud UP where it can be gravel vac'd easily or sucked up by the HOB filter.
--don
Debris blocks up my Aquaclear HOB filters before it influences my UGF. I consider gravel vacs a necessary part of keeping any tank so UGF or not it has to be done, and that keeps a UGF clear to flow.
The amount of nitrifying bacteria in a tank is dynamic. You will see a curve depending upon 1. exhaustion of available nutrients; 2. accumulation of inhibitory metabolites or end products; 3. exhaustion of space.
Tanks are not just cycled. The bacteria life cycles are being renewed every day which is directly influenced by the 3 reasons above. Cycling a tank means you started a cycle that should be reliable. Having a smaller substrate for bacteria to live in also means it can be contaminated faster, inhibit proliferation at a time of nutrient flux, and provide more nutrients by volume.
If you have gravel then you need to vacuum, but UGFs do cause problems keeping it clean compared to just a plain gravel bed. Since it will trap debris out of reach of the gravel vac it is worse than a regular gravel bed.
Then you need to be cleaning your AquaClear more. And in any tank with an UGF there MUST be weekly thorough gravel vacuuming.
There is some variation in the amount of nitrifying bacteria. For example it will drop after a week of barely feeding. But it is pretty static and will macth the bioload. So unless you feed more or less, or add or remove fish, it will stay about the same. And even with variability, there is an upper limit. Even in my highly stocked tanks, canisters and HOBs have always been more than enough.
I use sand and have enough filtration and flow, so there is no vacuuming needed in any of my tanks. So all the debris ends up in the filters where it can be removed more easily.
Online prices are about as follows. They would be higher in stores where most people shop, and shipping is extra. But this is a minimum of what you would be spending on each setup:
Whisper 20: 14
Perfecto UGF 24x12: 12
Penguin 660 powerhead: 15
total:41
Whisper 40: 20
Whisper 60: 28
AquaClear 50: 30
You can go with the at minimum $41 total, assuming it only needs one powerhead and is a 20high not a 20long. Or you can pick any one of the other options and be done with and make things easier for yourself.
I personally do not like to pay more for less.
Then you need to be cleaning your AquaClear more. And in any tank with an UGF there MUST be weekly thorough gravel vacuuming.
There is some variation in the amount of nitrifying bacteria. For example it will drop after a week of barely feeding. But it is pretty static and will macth the bioload. So unless you feed more or less, or add or remove fish, it will stay about the same. And even with variability, there is an upper limit. Even in my highly stocked tanks, canisters and HOBs have always been more than enough.
I use sand and have enough filtration and flow, so there is no vacuuming needed in any of my tanks. So all the debris ends up in the filters where it can be removed more easily.
Online prices are about as follows. They would be higher in stores where most people shop, and shipping is extra. But this is a minimum of what you would be spending on each setup:
Whisper 20: 14
Perfecto UGF 24x12: 12
Penguin 660 powerhead: 15
total:41
Whisper 40: 20
Whisper 60: 28
AquaClear 50: 30
You can go with the at minimum $41 total, assuming it only needs one powerhead and is a 20high not a 20long. Or you can pick any one of the other options and be done with and make things easier for yourself.
I personally do not like to pay more for less.
I used an undergravel filter when I first got into the hobby and for a while had both undergravel and a Penguin 280. I took out the undergravel because it was too much work to maintain. What people are saying is right, they get alot of gunk trapped underneath them.
Not always good advice ... if the suction is too powerful the intakes can and if they are small enough WILL collect your fish and kill them in a matter of seconds. (assuming RUGF)
If you go real big you will want to put on some sponges ... to distrubute the suction more evenly - which will lower the flow rate so youre canceling out the benefit of going big in the first place. AND of course thats all dependent upon the size of fish you stock, but in a 20g I assumed rather small ...
This problem that is being debated is easily avoided. By using a reverse-flow undergravel setup with sponges on the powerhead intakes, the debris is trapped before it makes it under the filter plates or into the gravel. Rinsing a sponge prefilter once a week is no different than rising Aquaclear media once a week.
