Neocaridina Davidi Blue Velvet Shrimp Randomly Dying Off; Problem Or Nature?

HI all,

I'm still relatively new to the hobby (had my tank since March),
and I've come across another thing to worry about.

I have a 20 gallon tank with some cardinal tetras, a pair of hillstream loaches,
and what started out as a batch of 20 hobby bred mature blue velvets shrimp.
The shrimp have been getting busy and there's now quite a few,
the tank is rife with blue youngsters, to a point where I'm thinking of giving some away.
The colony has at least tripled since I bought the initial 20 back in march..

Only now there's something that started happening since a few days ago;
Every one or two days I have to fish a dead shrimp out of my tank.
I've removed 4 of them so far over the course of a week or so;
the first one had a weird translucent and orange color,
though that one might have been there for a day already.
The consecutive ones were all seemingly healthy looking adults.

I have done a 50% water change like I always do on sundays.
Water parameters all look good, tested with 2 different sets and a copper test.
Temperature is as it should be, measured with 2 different thermometers.
There is nothing funky in the filter as far as I can see.
No death in the tank other than the shrimp i've fished out,
and they probably haven't been dead for longer than 12 hours.

I've fed them shrimp specific pellets and catapa leafs, the tank is heavily planted,
so it should be an absolute paradise for these little critters.

I've read that this species lives for 12 to 24 months,
and I've had them since adults for about 7 months now..
SO... could this just be oddly coincidental natural old age deaths?
Or is there something happening that I haven't found yet?

 

HI sokonomI first there's nothing that stands out saying to me there's a disease in there so I think you can rule that out but the next time one dies can you take a close up photo of it in the tank, depending what temperature your running at could be a contributory factor along with age, I can't see any moult issues which I would not expect in a well mature tank anyway unless you gh is low, as for numbers I wouldn't worry to much but if you pass any on let it be the lower colour blue or light, looks like there's 1 or 2 pensioners in there as well,
If you've been doing 50% water changes since you had them your lucky they've not died of shock or moult issues but as it stands don't change anything, you say your perameters are ok and it's not that anyone distrust what your saying but to agree with you it would be good to publish them as any advise given will be on what you related to us and not what we think might be right

 

The pic only shows the older ones feasting on "snowflake" (whatever that is) in the morning,
but there's younguns the size of a gnat in there as well as some older plump looking ones.
Overall they seem to be thriving, with no deaths since march.

I'll be keeping an extra keen eye on them for now, but there's no popcorning or weird swimming going on,
they are all slick blue looking, no weird film or spots or discolored internals that could indicate illness.
I even bought a copper test to make sure they were alright.

The last one I picked out earlier today couldn't have been dead longer than 2 hours,
and it looked as clean and blue as I could want them to be.

Heres the log i've been keeping;




Acidity and hardness have been super stable, ammonia has been gone since the cycling stage,
The trace amounts of nitrite could have been me just imagining the test fluid having the tiniest pink hue.
Nitrate was way high at some point but I got it under control now (EI dosing is finicky).
Phosphate has been steady, and ive seen people run that at 10ppm with shrimp, so I guess its cool.
Copper trace was so little it got barely picked up, even in .01 accuracy tests.
CO2 has been a light green on the dropper, though people say the accuracy on that stuff is iffy.
Temperature is 24'c or 75'f.

The water changes are always a bit of a dance, my shrimp are extremely curious.
I have to admit there has been an accident or two with an unfortunate casualty.
I have to vacuum with an acrylic unfiltered tube because of super fine grit sand,
and they just divebomb on top of anything I poke, I can only squeeze the hose so fast.

Plants are growing, fish are playing, everything is eating well.
So seeing 4 of my blueboys drop in a row is a bit disheartening.
If the casualties keep coming, i'm not sure what to do about it.

 

You are well on top of your game here, and can see you only wanted an opinion now to what I think you already knew, 22.5 is best but they breed that little bit slower 24c is fine and may just knock a couple of months off their lifespan which you probably know anyway, and as for water changes your know what can happen, I think your doing fine butty, if the casualties stay old then I think it's old age if you see babies die then it's another matter, with the temperature at 24 could well bd a factor, I have shrimp die regular as I've kept them for 10 years so there's always ones 18 month + so it's to bd expected but I still make sure it's old age

 

I have a tic where I tend to micromanage things a bit, which seems to come in handy in this hobby.
I got the thermos cranked for my shoal of Cardinal tetras, and even then its still a little cold for them.
Its making the shrimp hyper metabolize a little, but at the rate they have been breeding I was hoping for a happy equilibrium.
I'm aware it's a bit of a temperature mismatch, but they got gifted to me so I made due.
I might set up a nice little 5 gallon for these guys and look for a more tropical cleanup crew for my 20 gallon tank.
But only after first ruling out the possibility of them having some kind of weird shrimp blight though.

 

Theres no reason why you couldn't raise your temp to 25c even 26c for blues is not uncommon

 

You did mention you have tetras in there and I have seen my group aggressive with shrimp. I would not be shocked if my school jumped on one albeit slI'm chance if they sensed weakness. I too have lost some too on three different occasions one was over feeding and secondly was using excel and third was a water change. I temperate my water but, I saw one swim right into my poor and it was the one that died. I only do 25% water change every 2 weeks now.

 

About murder being afoot, bit of a sidestory but it explains some things, so;
I've only seen one cardinal show mild aggression sofar, but hes a bit of a special case because hes a little damaged..
The fishshop only had 9 of them in stock at the time, and number 9 had some damaged scales so they didn't want to sell it.
So then I asked what would happen to poor ugly timmy, he flat out told me he'd go in the freezer.
And me being the big soft sop I am, offered to take the uggo home with the rest of his brethren.
Hes been happy and healthy, but hes a bit more territorial than the rest of em,
so on occasion he lunges at shrimp that pop up behind a leaf in his "zone" of the tank.
I've never seen him actually touch a shrimp that way, much less kill one though.
Other than that, they show very little interest, even in the dead ones.

Overfeeding can be an issue for shrimp?
There is plenty to pick at in my tank, but I never thought it would outright kill them..
Should I pull the almond leaf I have in there? They seem rather fond of it..

Excel can kill shrimp? I assume you mean seachem flourish excel?
Do you have the exact reason why that can kill? i.e. which chemical does it?
The only thing that's changed in my tank at the moment they started dying is I halved my fertilizer dosage.
Having LESS fertilizer in the tank can't off a shrimp, can it?

Ive been doing waterchanges religiously since ive started,
and I've had a lot of people tell me that doing it every sunday is a bit overzealous.
My Estimative Index fertilizer program calls for it, but id gladly take a solution that lets me coast 2 weeks instead of 1.

 

@Solomomi, please don’t change anything your doing. 4 shrimp out of the hundreds you must have are not a big deal, I loss a shrimp a week but my tank is solid and mature. I know it seems like things are going down hill for you but honestly at this point you could make things worse but changing things up. The worst thing we do is jump to conclusions and manufacture a problem, that only makes things worse and often cause you to spend more money needlessly.
My advise relax and keep and eye out as Richie pointed out if another one died get a picture and post it and we might be able to have a better idea of what is wrong.

 

Another one bit the dust, this one can't have been dead for longer than an hour.
You can see the younger generation sitting nearby.
There's another 15 of them just to the left, feasting on some spinach pellets.
There's a few berried females hanging about as well.
Waterchange occurred 26 hours ago, reading a perfect 20/2, no nitrate/ammonia.

What I'm able to deduce from all this is that it only affects the older ones.
So this might very well just be old age, nature doing its thing.
You guys able to see anything wrong?

 

I don’t see anything, I know it’s frustrating but, I think your tank is setup right, how much of a water change did you do and was your replaced water close to your tank water in ph, and temperature?

 

As long as I know for sure its not me killing them, I don't mind.
Nature does its thing eventually, no amount of care can stop that.

I always do a 50% water change, to purge fertilizers (Estimative Index program).
pH is 7.5 going in, 7.3 coming out, which is expected with injected CO2, but no huge difference.
I always let the tap run until it matches tank temps before feeding it in through a diffusing sprayhead.
I use seachem prime, despite the fact that my tap water is technically already tank safe (20mg/l Cl).

Only thing I can think of is that maybe they have been gorging themselves on crumbs of fish food that make it to the bottom.
I can't really find an accurate measurement on what to feed 9 adult Cardinal Tetras and 2 loaches,
but they get 2 'smidgen' spoons of tetramin micropellets every day and one fingernail sized shimp pellet every other day.
And there's plants and an almond leaf for them to snack on if need be (they seem to love it).

Heres what their home looks like;



This is the most aggressive i've seen my tetras get around shrimp.

 

The colour on the first photo is the inside of the shrimp white or is it just the photo?
Have you had any young die?
What's the bps on your c°2

 

It looked a bit pale in the water, but once I got it out it seemed normally colored again.
Could this mean anything?

No younger ones have died, its been 5 sofar, and exclusively adults.

I can't tell you the bps on my CO2 unfortunately, i've been going by the dropper indicator.
Lime green when it turns off at 7pm, dark green when it turns on at 7am.

 

You did mention you have tetras in there and I have seen my group aggressive with shrimp. I would not be shocked if my school jumped on one albeit slI'm chance if they sensed weakness. I too have lost some too on three different occasions one was over feeding and secondly was using excel and third was a water change. I temperate my water but, I saw one swim right into my poor and it was the one that died. I only do 25% water change every 2 weeks now.

Wait... Flourish excel killed your shrimp?

 

Keep an eye on them all and note any colour change.
To much c°2 can lower ph which will kill shrimp so test you ph to see if its having an affect of causing big swings or lowering it to dangerous levels,
C°2 can also deplete you tank of oxygen suffocating you shrimp so make sure you have an airstone to compensate if necessary. Overdosing with anything can kill shrimp from c°2 to fertilizers as well as any chemicals
This is just something to think about as in could they be causing problems,
Let's go back to the beginning and the fact it's only the older ones dying I think its an age thing and until the babies start dying you've nothing to worry about
As we've said your doing nothing wrong from what I can see and the worst thing to do is start to change unnecessary things

 

Excel when dosed as directed is fine with shrimp.