What kind of filtration is right for me?

[InfinityARch]

So I'm currently working on getting a 120 gallon aquarium (48"x24"x24") set up. It has a 30 gallon (36"x12"x16") sump which is currently set up in a rather underwhelming fashion. My current plans for drainage are as follows: the system will drain via two "megaflow" style overflows tied together behind the tank with a 2" balance pipe. I intend to use a bean animal style drain with 1 full siphon standpipe in the far (left) overflow, 1 open channel (durso-style) standpipe in the near (right) overflow, and an additional backup drain plumbed through the back of the overflows. My goal is to circulate 720 gallons per hour between the sump and display tank, though I'd be open to going with lower or higher turnover rates if that made for better filtration.

The issues with this setup start once the water reaches the sump (pictured below) however. As you can see it's set up for a wet/dry filter, with water dropping straight out of the hoses onto a trickle plate. From what I understand, that's a recipe for an extremely loud filter, and considering this is going in an apartment with neighbors who would potentially be bothered by load gurgling and splashing audible through the walls, I need to make this system quiet. I'm planning on using it for freshwater, but would like keep the option to convert to saltwater open.

One person on reddit suggested converting the sump to use a fluidized bed filter. My own impression is that such systems are by far the loudest out of the various filtration schemes, but maybe I'm missing something; could I substitute (loud) air pumps and bubbles for (comparatively silent) circulation pumps, or would that not work. In order to keep the noise of splashing water down, I'll need to install extensions to the drain pipes that go below the water level in the first chamber (and add in a bunch of new baffles), so I would assume that rules out a wet/dry filter, and at the same time I'm concerned that simply running submerged media in the sump will be ineffective; the denizen of the tank I'm planning for will be a decently large and messy eater.


I'm grateful for whatever advice the community here at MFK can offer.

 

[twentyleagues]

Wet drys can be louder then submerged media. But it shouldnt bother your neighbors loud. If the walls are that thin everything someone did would be bothersome. It will be noisier in the room with the tank but other then that you should be good. Wey dry is a really good filter type for fresh water, it's really hard to beat its efficiency.

 

[Bertie07]

Wet dry filters are great, they may be noisy but in a stand it should be fine, I wouldn’t worry about it

 

[DIFish]

I have never had a a wet/dry filter so I cannot speak for the noise level, however I do have a fluidized bed with over 50 liters of k1 circulating. That being said, a fluidized bed can be quiet if you invest in a decent air pump and set it up properly. I can grab some decibel readings later to give you an idea of what “quiet” is. I also have a hard time believing neighbors will be able to hear either setup if done correctly.

 

[InfinityARch]

I have never had a a wet/dry filter so I cannot speak for the noise level, however I do have a fluidized bed with over 50 liters of k1 circulating. That being said, a fluidized bed can be quiet if you invest in a decent air pump and set it up properly. I can grab some decibel readings later to give you an idea of what “quiet” is. I also have a hard time believing neighbors will be able to hear either setup if done correctly.

How much of a safety margin do I want in terms of waste capacity? My own reading suggests at full size my fish will consume at most 45 g of food a day, and probably quite a bit less since that study was about maximum daily rations rather than the more conservative feeding regimen of a home aquarium. If I'm using K-1 media, based on the manufacturer's recommendation (1 liter media/gram food) I'd want 10-16 liters of media, which in turn means 10-16 LPM of air. That will definitely fit into the sump with room for mechanical filtration and a chamber to isolate the return pump.

Looking on amazon I see some air-pumps in that range which are allegedly quite quiet, but do you have a recommendation?


One other question I have is whether there's an accurate (rather than rule of thumb) way of determining how much water will drain from the tank to the sump in the event of a power outage? Right now I'm using the volume of the space between the top of the overflows and the tank rim plus the approximate volume of 7" of water in the two overflows (since this is using a full siphon drain), but others have said I shouldn't expect water to be more than .5" above the top of the overflow, which would considerably reduce the amount of drainage I need to account for.

 

[DIFish]

How much of a safety margin do I want in terms of waste capacity? My own reading suggests at full size my fish will consume at most 45 g of food a day, and probably quite a bit less since that study was about maximum daily rations rather than the more conservative feeding regimen of a home aquarium. If I'm using K-1 media, based on the manufacturer's recommendation (1 liter media/gram food) I'd want 10-16 liters of media, which in turn means 10-16 LPM of air. That will definitely fit into the sump with room for mechanical filtration and a chamber to isolate the return pump.

Looking on amazon I see some air-pumps in that range which are allegedly quite quiet, but do you have a recommendation?


One other question I have is whether there's an accurate (rather than rule of thumb) way of determining how much water will drain from the tank to the sump in the event of a power outage? Right now I'm using the volume of the space between the top of the overflows and the tank rim plus the approximate volume of 7" of water in the two overflows (since this is using a full siphon drain), but others have said I shouldn't expect water to be more than .5" above the top of the overflow, which would considerably reduce the amount of drainage I need to account for.

In terms of weight capacity, I would determine the MAX possible size/weight of all planned/future fish and plan for food for that. For example I have a silver arro, do I expect it to grow to 40 inches? No, but my filtration could support food for that kind of beast. So in your case maybe 10-15 liters of K1 for 50-75 grams of food a day. As far as an air pump goes, I know the standard seems to be 1-2 but I think it’s a bit overkill. Maybe .5-1 lpm per liter. The only pump I have tried in that range is the 15LPM Alta air, and it is pretty silent. Water from your tank will drain from the lowest point. Don’t forget to include return lines if they are below the overflow. If your returns are above the overflow then you can just do the overflow and pipe volumes. I know you said you were in an apartment so plumbing a drain to carry extra water is probably a no go, but you could invest in a uninterruptible power supply, which would give you peace of mind and be much cheaper than a flood.

 

[ragin_cajun]

Why do you need K1? It's a 120 gallon tank in an apartment. You want it to be quiet, then choose a filtration method that is most amenable to that design requirement.

I'm sure you COULD make a K1 filter run "quiet" if you chose the proper air pump, and if, and if ..... but why? If you tell me you really need K1 because your tank will need massive bio-filtration for very large animals that will be fed very often, then OK. but......I don't think you're gonna have that in a 120 gallon tank.

I have a 540 gallon tank, I installed the simplest filtration method possible in my sump, and I'm glad I did. Filter socks, drain outlets below the sump water line, filter media in a nylon laundry bag. Quiet, effective, reliable.

 

[InfinityARch]

Wet dry filters are great, they may be noisy but in a stand it should be fine, I wouldn’t worry about it

Won't the noise reduction from the siphon drains be completely nullified if the drain outlets are above the water level in the sump, which is required for wet-dry filtration?

Why do you need K1? It's a 120 gallon tank in an apartment. You want it to be quiet, then choose a filtration method that is most amenable to that design requirement.

I'm sure you COULD make a K1 filter run "quiet" if you chose the proper air pump, and if, and if ..... but why? If you tell me you really need K1 because your tank will need massive bio-filtration for very large animals that will be fed very often, then OK. but......I don't think you're gonna have that in a 120 gallon tank.

I have a 540 gallon tank, I installed the simplest filtration method possible in my sump, and I'm glad I did. Filter socks, drain outlets below the sump water line, filter media in a nylon laundry bag. Quiet, effective, reliable.

My understanding is that a fluidized K-1 fitler is extremely efficient in terms of the amount of waste processed for a given volume of media, which means it takes up less of the volume in the sump versus submerged media. My understanding is that compared to submerged media fluidized and wet/dry are upwards of 10x more efficient, so having 12 liters of K-1 or W/D versus 120 liters of submerged media (which incidentally is larger than the volume sump) seems to be the obvious choice, and wet/dry is not an option since my drain exits must be below the waterline in the sump. If I can achieve a similar bioload capacity with submerged media, I'll gladly do it.

 

[Bertie07]

Won't the noise reduction from the siphon drains be completely nullified if the drain outlets are above the water level in the sump, which is required for wet-dry filtration?




My understanding is that a fluidized K-1 fitler is extremely efficient in terms of the amount of waste processed for a given volume of media, which means it takes up less of the volume in the sump versus submerged media. My understanding is that compared to submerged media fluidized and wet/dry are upwards of 10x more efficient, so having 12 liters of K-1 or W/D versus 120 liters of submerged media (which incidentally is larger than the volume sump) seems to be the obvious choice, and wet/dry is not an option since my drain exits must be below the waterline in the sump. If I can achieve a similar bioload capacity with submerged media, I'll gladly do it.

Well what happens is that the drip tray should have a couple mm of water in it to be most effective so if you can put the drains in the mm of water then it should be quite. Also if you put sponges or filter floss in the drip tray and have the hoses touching them then the sound would also be quiet

 

[InfinityARch]

Well what happens is that the drip tray should have a couple mm of water in it to be most effective so if you can put the drains in the mm of water then it should be quite. Also if you put sponges or filter floss in the drip tray and have the hoses touching them then the sound would also be quiet

My understanding is that this style of drain should exit at least 1" below the waterline of the sump; a couple mm won't cut it. I suppose an option would be to have the wet dry tower in a second chamber after an initial baffle where the water exits the drain, but I've never seen that kind of setup used, and have no idea whether it would work particularly well.