Does sponge filter pore size matter?

[LoachTruther]

I have two tanks running with sponge filters. Both have stable parameters with pH around 7.8, Nitrites at 0, and nitrates around 30 ppm (hopefully these go down as my plants settle in). Every time I take a reading, ammonia is under 0.25 ppm, barely detectable, but still there. I've begun to wonder if I might be able to get them all the way to zero, and I have two ideas/questions about it.

My first theory is about the sponge filters. The sponge filters I have are extremely fine with teeny tiny pores, and I've heard people say this can decrease their efficiency. I've watched the co-op videos and Cory's objection to fine-grade sponges is that they need to be cleaned more because they clog more easily, but he doesn't comment on whether they're less efficient than coarse sponges, even when properly cleaned (I squeeze mine out in tank water every other week). Does anyone know if switching to coarser sponge filters will help get that last stubborn bit of ammonia down?

My second theory is about plants. I've filled each tank with as many plants as I can, do I just need to wait for them to settle into the tank and let them take up that ammonia?

[Toobit67]

How long have these tanks been running?  What livestock do you have in them?

[Brian]

Do you use API or Prime or Fritz?  I know people have reported false readings with Prime and Fritz Complete Water Conditioner.  I think API might do the same.  

[LoachTruther]

1 minute ago, Toobit67 said:

How long have these tanks been running?  What livestock do you have in them?

One is 7 months old with an axolotl, and the other is 3 months old with a betta and a whole bunch of ramshorn snails! The axolotl tank has two large sponge filters, a few Java ferns and anubias, some Marimo moss balls, and some salvinia, and the betta has one small sponge filter, some Brazilian penny wort, dwarf hair grass, a crypt tropica, a red dwarf lily, and a dwarf tiger lily.

[LoachTruther]

6 minutes ago, Brian said:

Do you use API or Prime or Fritz?  I know people have reported false readings with Prime and Fritz Complete Water Conditioner.  I think API might do the same.  

My house is actually serviced by a small water company with access to a local aquifer whose water requires no treatment, so my tap water is chlorine/chloramine and heavy metal-free, and I don’t need to use any water conditioner. But it might be worth a shot testing the kit with some bottled water or something to be sure it’s ok, thank you!

[Brian]

Does this tank have and substrate, decorations, drift wood or rocks?   
The bacteria you need is on all of those things.  
The pore size should not be an issue.  Pore size will determine how small or large the particles the sponge will collect.  
But, remember.....  even a sponge with larger pores as it clogs (fills with waste) it will collect smaller things.  This is why a sponge filter can go months without needing service and then it seems within days it is plugged.....

 

Good Luck

[Gideyon]

If it's consistent in both tanks, I'd test the water out of the tap. 

I found it odd on my own tank that I had about 0.25 ammonia, but nitrite was 0, and nitrate was between 5 and 10ppm.  But my tank is considerably younger than yours.  I need to give it time.  I'm also about to mess up the cycle again soon when I adjust my filter. 

But one thing I do to help with the cycle is API Quick Start.   I'm novice on this. But my understanding of the N-cycle is that if nitrates are present, you have the bacteria needed. But do you have enough?   It's possible that my 0.25 ammonia was because I had more waste than my BB could handle (again, my novice mind at work).   

I did a 30% water change (conditioned new water). Added another dose of API quick start.   I'll be testing the parameters again next week. 

[MJV Aquatics]

Although it's true that a fine pore sponge filter will clog more quickly than a coarse pore, it's debatable if moving water faster through any media improves BB efficiency. One might make a case that faster flows reduce BB's efficiency in oxidizing evil ammonia and nitrites. You can switch to more coarse sponges, but for your issue, if you keep the ones you have relatively 'clean' they should work for you. (the real advantage of the coarser sponge filter is they don't need to be serviced as often.

The plants you have are slow growers and will do little to absorb the ammonia your tank produces. For this you really need fast growing plants. Typically most floating plants do this the best and there are many...water sprite, water wisteria, frogbit, hornwort, and many others will convert ammonia into plant tissue eventually removed.

Edited March 6, 2021 by MJV Aquatics

[LoachTruther]

6 hours ago, Brian said:

Does this tank have and substrate, decorations, drift wood or rocks?   
The bacteria you need is on all of those things.  
The pore size should not be an issue.  Pore size will determine how small or large the particles the sponge will collect.  
But, remember.....  even a sponge with larger pores as it clogs (fills with waste) it will collect smaller things.  This is why a sponge filter can go months without needing service and then it seems within days it is plugged.....

 

Good Luck

I do have substrate and decorations, thank you!

[LoachTruther]

4 hours ago, Gideyon said:

If it's consistent in both tanks, I'd test the water out of the tap. 

I found it odd on my own tank that I had about 0.25 ammonia, but nitrite was 0, and nitrate was between 5 and 10ppm.  But my tank is considerably younger than yours.  I need to give it time.  I'm also about to mess up the cycle again soon when I adjust my filter. 

But one thing I do to help with the cycle is API Quick Start.   I'm novice on this. But my understanding of the N-cycle is that if nitrates are present, you have the bacteria needed. But do you have enough?   It's possible that my 0.25 ammonia was because I had more waste than my BB could handle (again, my novice mind at work).   

I did a 30% water change (conditioned new water). Added another dose of API quick start.   I'll be testing the parameters again next week. 

I'll try the tap water, and I'll think about the quickstart. I seeded the bacteria in my tank from a 5 y/o aquaponic system in my garage so I'm not sure if its necessary, but I've also never tried quickstart, so who knows! Thanks

[LoachTruther]

2 hours ago, MJV Aquatics said:

Although it's true that a fine pore sponge filter will clog more quickly than a coarse pore, it's debatable if moving water faster through any media improves BB efficiency. One might make a case that faster flows reduce BB's efficiency in oxidizing evil ammonia and nitrites. You can switch to more coarse sponges, but for your issue, if you keep the ones you have relatively 'clean' they should work for you. (the real advantage of the coarser sponge filter is they don't need to be serviced as often.

The plants you have are slow growers and will do little to absorb the ammonia your tank produces. For this you really need fast growing plants. Typically most floating plants do this the best and there are many...water sprite, water wisteria, frogbit, hornwort, and many others will convert ammonia into plant tissue eventually removed.

Thanks so much for the feedback! Would salvinia and red root floaters also work?

[FishyJames]

A fine sponge filter has a larger surface area resulting in more biological filtration.  Just clean it regularly to keep efficiency up.

[Daniel]

14 minutes ago, FishyJames said:

A fine sponge filter has a larger surface area resulting in more biological filtration.  Just clean it regularly to keep efficiency up.

Perhaps. But if there is more than enough biological filtration on sponge filters with the larger sized pores, then adding more than enough doesn't really add anything, except for having to clean it more often.

[Brandy]

11 hours ago, Daniel said:

Perhaps. But if there is more than enough biological filtration on sponge filters with the larger sized pores, then adding more than enough doesn't really add anything, except for having to clean it more often.

I find that my larrge pore ACO sponge do need cleaning less often, but the fine ones do more mechanical filtration....until they clog. I get the best of both worlds by running one of each on some of my messier larger tanks. Arguably a HOB would do the mechanical filtration better.

[Maggie]

15 hours ago, Daniel said:

Perhaps. But if there is more than enough biological filtration on sponge filters with the larger sized pores, then adding more than enough doesn't really add anything, except for having to clean it more often.

I agree 110%!! 🙂

[Ben_RF]

On 3/6/2021 at 2:08 AM, Brian said:

Do you use API or Prime or Fritz?  I know people have reported false readings with Prime and Fritz Complete Water Conditioner.  I think API might do the same.  

You can get a false reading from API too.

[gardenman]

I use fine pore sponge filters and I don't find that they clog. (I also use mechanical filtration on most tanks with a HOB or canister.) I think a lot of the "gunk" people think is clogging their filter is actually the bacteria that's living in the filter. With a "normal" water flow most sponge filters lack the power to suck in a lot of debris. They're more designed to slowly circulate water through the sponge. Most debris will settle to the bottom of the tank and become mulm rather than get trapped in the filter. If you're using a powerhead on a sponge filter they're more likely to clog, but most sponge filter makers don't recommend using powerheads as slower water flow through a sponge filter is better. If you look at videos of Matten filters in use the water flow is often absurdly slow considering the amount of sponge surface area. When I add food to my one tank that's only filtered by a sponge filter, none of it gets drawn to the filter. A flake will float down an inch (or less) from it and just drop straight down and not move towards the filter at all. They really don't suck in debris with a typical waterflow. I think people see all of the "gunk" that comes out when you clean one and assume it was clogged, but I'm pretty sure that much of what they're washing out is the bacteria they want to keep.

[MJV Aquatics]

19 hours ago, Daniel said:

Perhaps. But if there is more than enough biological filtration on sponge filters with the larger sized pores, then adding more than enough doesn't really add anything, except for having to clean it more often.

Yep - The size of the BB colony(ies) is relative to O2 and the available food so more or less surface area on a sponge would likely have little impact...especially when we consider the vast surface area of the substrate in the established tank.