This started as one post but I ended up separating this into two threads one part in the Shrimp Forum and one part in the Crayfish forum.
Ever since Mustafa updated his shrimp keeping guide I’ve been doing the whole leaf litter thing. What I was doing before this update was working fantastically and since its not like my previous setup interferes with leaf litter I thought I would share it:
When I first got Cherry Shrimp I wasn’t terribly successful in raising them. They would breed and I would get offspring but It was irregular and few in numbers. A massive population of Ramshorn snails seemed to annihilate any added food before the Shrimp could do much damage to it. The snails just kept the tank so “clean” the shrimp must have had to eat less desirable/nutritious sources of food.
So I thought “What kind of thing would provide a food source that is more accessible to shrimp than to snails?”…I naturally thought of sponges…Shrimp seem to love grazing off them and microorganism seem to flourish in/on them and the pitted and gaping surface means that more nimble thin appendages get better access to available food…
So I took a dead living “wool” sponge like this

and put it in an overpopulated guppy tank for a week to let it soak and accumulate a healthy population of critters and bacteria…(Also I wanted to make sure it wasnt going to kill off all my shrimp

I then put the sponge in the shrimp tank…the shrimp immediately attacked the sponge…the smaller ones crawling deep into the holes and pits in the sponge grazing in areas that are totally inaccessible to larger shrimps….(good place to hide too)
After this addition to their tank my cherries began flourishing…reproducing and growing at a pace that I had only heard about from other enthusiasts…I also developed a much more vigorous population of copepods in this tank as well (almost swarm like)….
When Mustafa recommended leaf litter I tried it out but the shrimp seem way more interested in the dead sponge. The majority of their time seems fighting over prime spots on the sponge….I still keep leave litter in the tank but the whole population spends less time amongst the dead leaves as they do on the dead sponge….
Really most of their time is spent now just grazing off the sponge seemingly only leaving it when it gets to crowded or their full….
In retrospect I don’t think I should’ve been surprised… I imagine it’s a similar situation as leaf litter.
The sponge has been shrinking in size over the 5 months its been in the tank (Ive never removed it since its been in there and it kind of looks like a rock from a distance now since it’s a totally different color than what it was at the start. It is probably being broken up and decayed with the help of a slew of various microorganisms.

(It used to be so much bigger)
And since it was a living thing I imagine that the types of things breaking down a sponge are the same types of things breaking down leaves….and all these “things” the shrimp seem to love eating…(or the things that are eating the things that are breaking the sponge down… whatever)
So I don’t really know if people have tried this before….but its worked better than great for me (maybe even an alternative to leaf litter? Because one large sea sponge takes up a good spot in a tank and you don’t have to bother with removing old leaves)…and I think the dead living sponge looks really cool in a tank…which is a plus….(leaves look cool (at first) too though that’s why I like both : ) )
So at first I only had this one tank with the sponge in it…So it was tested for about 5 months…maybe longer now because Ive been sitting on this post for a while now…..but after this one tank with the sponge started doing better than all my other tanks I have now added a sponge to my crayfish tanks, my crayfish shrimp mix tanks….my crayfish/shrimp/planted/guppy tanks….so Ill soon have an idea of how the Dwarf crays respond to this set up (but they were breeding very well already)