has anyone ever undersized their (bio) filtration?

[CT_]

By that I mean, have you ran a filter and had it be unable to keep up with the ammonia or nitrite, and then upgraded your filter/media and had it keep up?  I'm just wondering how much is really needed.  Part of me thinks that all you need is a power head/airstone to mix the water.  Assuming you're not running a bare tank.

 

To me my HOB is really just for mechanical "polishing" and I put sponge in there too because I'm too afraid to be wrong.

[eatyourpeas]

I am always paranoid about not having enough as well. I overdo it, of course. Even my 3 gallon tank has a canister filter. 🤪

[Odd Duck]

I have excess biofiltration on everything.  And lots of plants.

[Widgets]

There are posts of tanks with no filter. That seems like it would be the limit of underfiltered, just relying on water flow and oxygenation. I do not have the discipline for that style tank, as I know I will keep adding until I overpopulate. My 37g has an Aqua Clear 110 full of ACO sponge, and an UGF with power heads.

[Minanora]

Well.... my guppy grow-out I had to keep adding, and adding hunks of sponge, a rock, plant cuttings, power head, more sponge. At the height of the population (140+ juvenile guppies) It was absolute chaos. 20G high tank with a 50G rated HOB, Several stacks of foam with a rock to hold it down, plant cuttings all over the place, a sponge filter and the spinny wheel (bio wheel) from my retired penguin filter just floating around. Lol. I was having to change water every other day to keep up with the nitrates. CHAOS.

I'm sure that with more water volume it would be easier.

Short version, yes, I've had to add surface area to keep up with the need for biological filtration. Children test all things. Even fish children!

[modified lung]

I have nothing but 0.3 liters of K1 media each in a couple 10 gal bare bottom tanks with no problems. Theoretically that's over 3 times what I need to cycle 1 ppm total ammonia in a day.

[Brandon p]

On 3/15/2022 at 8:01 PM, CT_ said:

By that I mean, have you ran a filter and had it be unable to keep up with the ammonia or nitrite, and then upgraded your filter/media and had it keep up?  I'm just wondering how much is really needed.  Part of me thinks that all you need is a power head/airstone to mix the water.  Assuming you're not running a bare tank.

 

To me my HOB is really just for mechanical "polishing" and I put sponge in there too because I'm too afraid to be wrong.

Every hob should have a sponge in it. Mine the Ceramic cylinders the a sponge. That small floss or plastic slats is meant to be a place for bacteria to grow and then the floss I in the front so I usually is meant to polish. There has been an occasion where I have added a polishing cloth with a sponge if I have a tank that needs it but normally I don’t I just have the sponge in the ceramic.

On 3/15/2022 at 8:01 PM, CT_ said:

By that I mean, have you ran a filter and had it be unable to keep up with the ammonia or nitrite, and then upgraded your filter/media and had it keep up?  I'm just wondering how much is really needed.  Part of me thinks that all you need is a power head/airstone to mix the water.  Assuming you're not running a bare tank.

 

To me my HOB is really just for mechanical "polishing" and I put sponge in there too because I'm too afraid to be wrong.

Every hob should have a sponge in it. Mine the Ceramic cylinders the a sponge. That small floss or plastic slats is meant to be a place for bacteria to grow and then the floss I in the front so I usually is meant to polish. There has been an occasion where I have added a polishing cloth with a sponge if I have a tank that needs it but normally I don’t I just have the sponge in the ceramic.

 

@CT_what filter do run now

[CT_]

I run a tidal 35.  I'm not really suggesting anyone throw out their sponge, and mine is full of sponge with a top layer of floss.  But I just have this nagging feeling that it all doesn't really matter, and its just flow and mixing that matters unless you're running a bare tank.

 

I'm too afraid to try it but I'm wondering if anyone else has on purpose or by accident.

[Brandon p]

I think it matters but if you have lots of plants the the surface is mixing you have substrate and animal numbers you could get away with it if you are doing water changes enough. The main reason for all the filters is one toe grow bacteria to break down the bad stuff and second take out debris that is of a size you don’t want to see. I a fan of having as much good bacteria growth as possible but it gives you a little extra leeway. If bacteria did matter no one would cycle tanks. I do agree that you could get away with no filter if you have the right set up and are very diligent. Somethings you can’t control you was recent in the hospital for a bit and missed my water change, most of the time no big deal, but it was my discus and there water change has premixed water to lower the ph. Came home and discus were dead but all the other fish in the tank were fine.

[modified lung]

On 3/15/2022 at 7:38 PM, CT_ said:

I run a tidal 35.  I'm not really suggesting anyone throw out their sponge, and mine is full of sponge with a top layer of floss.  But I just have this nagging feeling that it all doesn't really matter, and its just flow and mixing that matters unless you're running a bare tank.

 

I'm too afraid to try it but I'm wondering if anyone else has on purpose or by accident.

You're right about this. If it's fully populated with bacteria, there's enough surface area in the top quarter inch of your substrate to handle the nitrogen load in most aquariums. I have an unfiltered 20 gal high filled with hornwort where I breed rosy loaches. I just push water from the top down toward the substrate with the smallest pump I could find. The main advantage of a filter, if you have substrate, is that it quickly pushes all your water through an area of highly concentrated surface area faster which makes biofiltration more efficient, especially if you're overfeeding.

[Kathy F]

Yes, not intentionally though.   I had a 40 breeder with three lionchus and my fluval canister filter broke instead of running to the store to buy another filter I decided to use two large sponge filters (one was already fully cycled).   There was always .25 to .5 PPI of ammonia in the tank after that because there wasn't enough biological to keep up with the load.   I wasn't upset about it since I was already in the process of upgrading them to 75 which is why I didn't immediately run out and buy another expensive filter.    The 40 breeder is still running with the same two sponge filter but now houses mollies, corydoras and loaches.   I only ever get readings of 0 nitrites, 0 ammonia 10-40 nitrates since the sponges are more than adequate to handle the job of the 40 breeder's new bioload.  

[Brandon p]

On 3/16/2022 at 12:51 AM, Kathy F said:

Yes, not intentionally though.   I had a 40 breeder with three lionchus and my fluval canister filter broke instead of running to the store to buy another filter I decided to use two large sponge filters (one was already fully cycled).   There was always .25 to .5 PPI of ammonia in the tank after that because there wasn't enough biological to keep up with the load.   I wasn't upset about it since I was already in the process of upgrading them to 75 which is why I didn't immediately run out and buy another expensive filter.    The 40 breeder is still running with the same two sponge filter but now houses mollies, corydoras and loaches.   I only ever get readings of 0 nitrites, 0 ammonia 10-40 nitrates since the sponges are more than adequate to handle the job of the 40 breeder's new bioload.  

Sponge filter work fine and many people just use sponge filters. I know people that get rid of canister or hob for sponges

[Kathy F]

On 3/16/2022 at 1:33 AM, Brandon p said:

Sponge filter work fine and many people just use sponge filters. I know people that get rid of canister or hob for sponges

If there had been enough biological, then yes it would have worked but there wasn't.   My API test kit reflected exactly that;  the results were always testing .25 to .5 ammonia, 0 nitrites and 10-40 nitrates for the 2 weeks they were in the tank until I could move them.   If I had kept them the 40 breeder then I absolutely would have had to find a way to add more biological filtration but it was a stop gap since I was shuffling fish around.  

[Guppysnail]

On 3/15/2022 at 8:01 PM, CT_ said:

Part of me thinks that all you need is a power head/airstone to mix the water.  Assuming you're not running a bare tank.

I believe you are correct and why is because I did it as a kid. My very first tank as a 7 year old kid was a tank and air pump purchased at a yard sale. I knew nothing about fish keeping. I went to the creek grabbed mud and rocks. I made the rocks into a volcano with the bubbler under it so it seemed like an active volcano. 
The rocks being from in the creek apparently already had Ben bacteria that I knew nothing about. As long as I changed water (learned from killing many critters by not changing water) it kept critters just fine. Being a kid I got forgetful and would forget to change water over time water changes became less needed and fish did fine ( I now know this as fish in cycling with seeded hardscape). This ran just fine with no plants no dead fish after I got it set up and running for awhile.  
My understanding of the biological function of a filter is just aerated water moving over the area bacteria is attached so it can access both o2 and the ammonia   
This may be an oversimplification please remember I was only 7 so be kind. 😁

[Brandon p]

On 3/16/2022 at 3:19 AM, Kathy F said:

If there had been enough biological, then yes it would have worked but there wasn't.   My API test kit reflected exactly that;  the results were always testing .25 to .5 ammonia, 0 nitrites and 10-40 nitrates for the 2 weeks they were in the tank until I could move them.   If I had kept them the 40 breeder then I absolutely would have had to find a way to add more biological filtration but it was a stop gap since I was shuffling fish around.  

I run 2 55 gal tanks with 2 sponge filters and I was running the 75 with them. The 75 I removed them because I didn’t like the look in the tank. They worker fine. I have more issues with the canister. I think thank the reason that we have more and more filters all the time. Some work for people and then that filter is not working for someone else so come up with something new. I’m trying a UGF with 15 ppi and moss over that. For me sponges may work better because I don’t keep my tank super clean. I do clean the front glass I have lots of drift and I’m gassing plants plus there is pothos in most tanks. If the sponges weren’t working for you I’m glad you changed instead losing fish. 

[Kathy F]

On 3/16/2022 at 9:00 AM, Brandon p said:

I run 2 55 gal tanks with 2 sponge filters and I was running the 75 with them. The 75 I removed them because I didn’t like the look in the tank. They worker fine. I have more issues with the canister. I think thank the reason that we have more and more filters all the time. Some work for people and then that filter is not working for someone else so come up with something new. I’m trying a UGF with 15 ppi and moss over that. For me sponges may work better because I don’t keep my tank super clean. I do clean the front glass I have lots of drift and I’m gassing plants plus there is pothos in most tanks. If the sponges weren’t working for you I’m glad you changed instead losing fish. 

Again, I don't think you are getting what I'm saying.   There was not enough biological filtration for 3 lionchus point blank.   It had nothing to do with the type of filtration, it had to do with the amount of biological surface available vs the stock bioload in my tank.  

Edited March 16, 2022 by Kathy F