I feel like air driven sponge filters be revisited.

[snowballs99]

I do notice a lot of people are able to grow HC carpets and mini dwarf hair grass carpets with just a good aquasoil using a sponge filter. In theory, it should degass a lot more co2 which aquasoil bioactivity generates. This should be bad, but it doesn't seem to actually matter in the end.


Hell, here's an even better example.

It seems the commonality is FRESH SUBSTRATE.

I like sponge filters because it also has some other benefits.
-Can't accidentily gas your fish with an airstone running if your also injecting.
-0 Surface film.
-Livestock notably more active.
-Tank seems more stable, bacteria probably works better with more oxygen.
-Cheap too.

I remember on some of my co2 tanks would always get dust algae on the glass that comes back no matter what. Everytime I added airstone etc it would pretty much never come back after you removed it.

 

[ElleDee]

Sponge filters have a lot of value in shrimp tanks for the reasons you've listed, but I think success with low tech carpeting doesn't depend on a particular filter type as much as the usual factors of success (active substrate, controlling organics, appropriate lighting, etc.). But IMO one of the delights of giving up CO2 is being able to get away with incredibly basic equipment, including the humble sponge filter.

I will say that while I understand the issue with CO2 outgassing conceptually, I only run non-CO2 injected tanks and yet I've never seen a negative outcome from increasing gas exchange. I'm not totally sure why that is - am I not really losing that much CO2 to the air compared to how much the tank is generating? Do the benefits of the increased oxygen outweigh the lost CO2, or is the oxygen directly contributing to the generation of CO2? I imagine the answer is one of those, but I'm not sure which exactly. My current thinking is that it's an overplayed fear based in older thinking that's due for a revisiting.

 

[snowballs99]

Sponge filters have a lot of value in shrimp tanks for the reasons you've listed, but I think success with low tech carpeting doesn't depend on a particular filter type as much as the usual factors of success (active substrate, controlling organics, appropriate lighting, etc.). But IMO one of the delights of giving up CO2 is being able to get away with incredibly basic equipment, including the humble sponge filter.

I will say that while I understand the issue with CO2 outgassing conceptually, I only run non-CO2 injected tanks and yet I've never seen a negative outcome from increasing gas exchange. I'm not totally sure why that is - am I not really losing that much CO2 to the air compared to how much the tank is generating? Do the benefits of the increased oxygen outweigh the lost CO2, or is the oxygen directly contributing to the generation of CO2? I imagine the answer is one of those, but I'm not sure which exactly. My current thinking is that it's an overplayed fear based in older thinking that's due for a revisiting.

My thoughts as well.
Effect of Extra oxygen/surface exchange seems to be bit under explored at least in CO2 tanks.

The focus is heavily on retaining CO2, but Im not sure if a lot of pickier species require anything more than say 15ppm which is pretty easy to achieve with a basic diffuser.