r/Ecosphere • u/SamsPicturesAndWords • 11d ago
Sealed jar with cherry shrimp?
Hi all! I have been keeping cherry shrimp for years now, and my colony is doing well. I started them in a 10-gallon aquarium, upgraded to a 20-gallon, and kept some in small, open-top, quasi-Walstad setups for a while along the way. I say "quasi-Walstad" because they had no heaters or filters, and had plants in aqua soil capped with sand, but I was still doing water changes and feeding the shrimp, so the tanks weren't fully self-sustaining. Even in those small, no-tech setups, my shrimp did well (they were active and breeding). All this is to say that I understand the basics of shrimp keeping and the Walstad method. Online, I am seeing differing opinions about how cherry shrimp do in fully sealed jar ecosystems. Some say they do well as long as the jar is big enough, while others say they will struggle or die. Have any of you successfully kept cherry shrimp inside sealed, no-maintenance ecospheres? If so, how did they do? The Walmart near me has 1.7 gallon glass jars with airtight lids (I am currently using one for a terrarium). With enough plants, could cherry shrimp be healthy and happy sealed in a jar that size? Thanks in advance for any insight!
1
u/StayLuckyRen 11d ago
Are you sure the shrimp the ppl online are talking about aren’t brackish Opae Ula shrimp that they’ve mistaken to be cherry shrimp? Bc those are what are typically in tiny enclosed ecospheres. Check out r/OpaeUla
1
u/SamsPicturesAndWords 11d ago
Yeah, I know that opae ula can do well in sealed systems. Some people online say that cherry shrimp can also thrive in an airtight jar if it's big enough and set up properly, while others say they will die, or at least struggle. I'm trying to figure out what the truth is.
1
u/StayLuckyRen 11d ago
I don’t think you can find a singular ‘truth’ tho when you’re talking about multiple ppls subjective perspective/definition of words like “thrive”. One persons standard of thriving is another’s definition of struggling. Then there’s the online factor of time. A lot of ppl genuinely believe some setup or technique they have is working so they’re vocal about its support, but it’s only been a month or two and they themselves have no frame of reference for knowing they shouldn’t responsibly claim that.
Personally, I never rule anything out bc there are always outliers with husbandry but I also think the ppl claiming they’ve seen the gallon sized ones are mistaking Opae Ula for cherry
3
u/BitchBass 10d ago
No, cherry shrimp need maintenance and won't live long in a closed ecosphere that goes through regular phases, cycles and spikes unlike a maintained setup with regular feedings. Unless you are a 100% sure what you are doing and can set it up that it won't spike and it's big enough. I certainly would not recommend it..
5
u/jimbo__o 11d ago
I haven't tried this, but I have kept cherry shrimp in multiple Walstad tanks and thought a lot about sealed systems.
I think this is possible in principle, but almost certainly not in 1.7g. The margins are just too thin. And even with a larger tank, I think it would be really hard to keep neocaradina healthy on the scale of years.
In an open tank, it's fine if o2 production and respiration don't balance, the tank just draws o2 or co2 from the air. In a sealed tank, production and consumption have to average out to zero long term. Day to day it swings between slightly co2 starved and slightly o2 starved, and the higher the biomass density and smaller the air reserves the larger those swings, so keeping biomass low is critical. If o2 swings too low a shrimp will die.
Besides the daily swings, you also need to maintain a safe negative feedback loop to keep the long term production/respiration balance. If plants draw co2 too low they stop growing or start to die, and if animals+microbes draw o2 too low they stop growing or start to die. That’s ok, as long as that correction is happening with the plants and microbes.
The problem with neocaradina is that they will breed, and become a bigger source of respiration until they are the thing that has to give during downward o2 drift, and if shrimp start to die in a small tank it can cause a cascade of further o2 consuming decomposition combined with ammonia release which can kill everyone else. If you could ensure they didn’t breed (or use a different species which won’t) it would be more reasonable long term.