Tannin effect on filter sponge color

[Werwa]

I apologize if this is a stupid question. I set up a 20 gallon long planted aquarium for my betta. I added 9 pigmy corydoras and a few snails. I recently added Indian Almond leaves, cones, driftwood and I have a nice tint to the water. I want to add RCS. Because I want reduced current for the betta I used an Aquaclear HOB filter suitable for 5 to 20 gallons. The sponge in the filter for mechanical filtration gets black pretty quickly. I was concerned it was too small for the biolodein the tank and was going to upgrade the filter and deal with the increased current, but it dawned upon me the black color may just be from the tannins. Can anyone please let me know if that is the case and how I can tell if the filtration is enough. Thank you in advance.

 

[Hanuman]

Coloration will be from several things but yes tannins will be part of those.
Your Aquaclear HOB filter basically has a 5x filtering capacity in relation to your tank size. Considering the stocking I would be more comfortable with a higher rated filter to be on the safe side but it's not that bad as it is. When it comes to filtration, more is better than not enough. You could also get a 2nd Aquaclear HOB filter of the same size so you could always have one running while the other is being cleaned.

 

[_Maq_]

Is the colour truly black? Or just dark brown?
(If black, you're in trouble, it's a sign of hydrogen sulfide.)

 

[Werwa]

Coloration will be from several things but yes tannins will be part of those.
Your Aquaclear HOB filter basically has a 5x filtering capacity in relation to your tank size. Considering the stocking I would be more comfortable with a higher rated filter to be on the safe side but it's not that bad as it is. When it comes to filtration, more is better than not enough. You could also get a 2nd Aquaclear HOB filter of the same size so you could always have one running while the other is being cleaned.

Thanks Hanuman, I like your suggestion about a higher rated filter. It actually only takes me minutes to clean the one I have. I will try to reduce the current by using a suctioned soap dish. I have seen this work with betta tank videos.

 

[Werwa]

Is the colour truly black? Or just dark brown?
(If black, you're in trouble, it's a sign of hydrogen sulfide.)

Thanks for your response Maq. I will be more observant when I check the color. I don't think it is black, but what other signs would I see if it was hydrogen sulfide? All the fish are doing well. Thanks.

 

[Nick potts]

I don't think it is black, but what other signs would I see if it was hydrogen sulfide? All the fish are doing well. Thanks.

If it were hydrogen sulfide you would know, it stinks like rotten eggs and your fish would likely be dead.

 

[_Maq_]

If it were hydrogen sulfide you would know, it stinks like rotten eggs and your fish would likely be dead.

And before this situation occurs, hydrogen sulfide gets neutralized by iron producing pitch black precipitate (iron sulfide). That's the last warning before nearing disaster.