Should I Replace Gravel with Sand?

[Slaphppy7]

Are you saying it’s not important for filter feeders like Corydoras?

I would agree with the above statement for loaches, but not corys.

Corys are bottom feeders, not filter feeders....they sift, but don't filter

 

[PheonixKingZ]

Corys are bottom feeders, not filter feeders....they sift, but don't filter

Corys are filter feeders... I’m pretty sure @CassCats told me this.

 

[Avel1896]

They detect their food thanks to their sensitive barbels, possibly spit water or even air to bring it up, and swallow it. Don't forget Corydoras have a 2nd respiratory system.

 

[dsch132]

I've heard from hobbyists all my life that sand can form gas pockets.

Don't fear the mulm (Mulm and Algae and Snails, Oh My!) Some Malaysian Trumpet Snails will make short work of any surface debris.

NO! There are a couple of reasons NOT to stir up sand substrates. First, you really don't want to push organics deep down under as that's when anaerobic decomposition of organic matter creates unwanted gases...and second, there's a world of beneficial biology that lives in the deep sand and their depth is partial based on the available oxygen. Stirring the sand upsets this very important environment. (see The Very Best Aquarium Filter) Lessons from or SW hobbyist friends.

This is a parroted myth. I've had deep (4") pool filter sand in my 60g low tech planted tank for 10 years and with the exception of planting plants, have never touched the sand!

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Now there may be something to be said for Dr. Kevin Novak's plenum approach (Using a Plenum in a Freshwater Aquarium) but I have yet to try this.

I've had other aquarists telling me to be worried about gas pockets for years and accepted their advice. Your post prompted a bit of extra research. Thank you!

 

[Essjay]

Cories take a mouthful of sand, sift through it for food then expel the sand through their gills. I'd call that sifting rather than filtering but that's just playing with words.

@PlasticGalaxy the cheapest option is Argos play sand. The prettier option is your choice of expensive fancy sands at the fish shop.

 

[PlasticGalaxy]

@PlasticGalaxy the cheapest option is Argos play sand. The prettier option is your choice of expensive fancy sands at the fish shop.

I think that's where we're going to get this one from actually... Two 15kg bags of it for £5 each. Yes please. I've heard that black diamond blasting sand can work as a good substitute, too.

 

[PheonixKingZ]

Cories take a mouthful of sand, sift through it for food then expel the sand through their gills. I'd call that sifting rather than filtering but that's just playing with words.

@PlasticGalaxy the cheapest option is Argos play sand. The prettier option is your choice of expensive fancy sands at the fish shop.

Oh, I thought it was called filtering.?

Regardless, they need smooth and small grained sand so they can eat.

 

[PlasticGalaxy]

Should I put my corys and kuhli loaches (if I can find and catch the little wormy things) in the 54L tank for the time being? Just as a "sooner rather than later" thing?

 

[Essjay]

To me, filtering is using something to catch all the bits but allow water to flow through. Like using a colander for straining veggies. Sifting is using a mesh or something similar to let the small particles fall through but keep the big particles behind. Like sifting flour through a sieve when making a cake.


(Years ago at university I shared a flat with another chemistry student and two medical students. The medical students were amused when I said it was time to filter the vegetables for dinner )

 

[Avel1896]

Should I put my corys and kuhli loaches (if I can find and catch the little wormy things) in the 54L tank for the time being? Just as a "sooner rather than later" thing?

For how long ?

 

[PlasticGalaxy]

For how long ?

Up until I can get everything ready to begin replacing the substrate. So... maybe a couple of days. Five at the very most I'd say.

 

[Slaphppy7]

You can do it now, or later, doesn't matter

 

[AbbeysDad]

To me, filtering is using something to catch all the bits but allow water to flow through. Like using a colander for straining veggies. Sifting is using a mesh or something similar to let the small particles fall through but keep the big particles behind. Like sifting flour through a sieve when making a cake.

Well yes and no...you refer to mechanical filtration where particulates get trapped and removed from the water. But there is also biological and sometimes chemical filtration as well. In biological filtration for example, nitrosomonas bacteria oxidize ammonia resulting in nitrites and nitrospira bacteria oxidize nitrites into nitrates. Then with chemical filtration, sometimes materials or resins are used to adsorb impurities from the water (e.g. activated carbon). Plants do an excellent job of filtering as these extract nutrients (aka pollution) from the water and convert it into plant tissue, often eventually removed through trimmings.
So filtration is more than may meet the eye.

 

[PlasticGalaxy]

You can do it now, or later, doesn't matter

Hmm... IF I can manage to catch them then I might.

 

[Slaphppy7]

Hmm... IF I can manage to catch them then I might.

Easiest during a WC, when the level is low