RCS displaying unsettling behaviour!

[Human Shrimp]

I bought you first  5 red cherry shrimps or my 5.5 gallon tank two months ago, they did fine for the first month and most of the second month that I've had them. I recently purchased two male shrimp to try and get some breeding, but suddenly, my cherry shrimp are not eating, they aren't moving, they aren't grazing. I almost never catch them grazing like they used to, I put in some spinach but they just ignored it, they aren't eating supplementary pellets. Yesterday one of the bigger females died, it looks like she failed to molt, baring the ring of death. So I lowered the temperature and did a water change, but their behaviour seems unchanged.

I haven't done any big changes, the biggest thing I did was remove a bit of moss that was too large for the tank (it was converted terrestrial moss that grew a bit out of hand reaching out and nearly to the top of the tank, but the shrimp never went in the moss, the just sat in the shade it produced) and add two male shrimp to entice breeding. Otherwise nothing has changed, water parameters are in check. Last week I purchased a piece of spiderwood that I thought would look good but I am now contemplating wether adding it could effect my cherries negatively. Should I be worried about my shrimp, and would it still be okay to add the driftwood?

[Revaria]

Can you give us your water parameters and depending on the size of the driftwood, it may drop the pH; its just something to keep in mind while utilizing it.  

[Human Shrimp]

Of course, parameters:

Temp: 70 F

pH: 7.6

Nitrite: 0ppm

Ammonia: 0ppm

Nitrate: 1ppm

kH: 4

gH: 7

[Revaria]

Those parameters look just fine and are similar to my cherry shrimp, from what you are telling us if the female did fail to molt then there was not much you could have done for it as it can sometimes just happen especially if it was a larger female as older shrimp have a harder time adjusting to new water parameters. Regarding the change in behavior there are a lot of variables in play right now, which may be affecting the shrimp.

 

1. What was the original temperature and how many degrees did you drop the temperature by and how much time did it take for you to drop the temperature. Dropping or increasing the temperature too fast can cause stress, which will not heavily effect healthier shrimp, but can hurt weaker shrimp.

2. The weather just turned a lot colder within the last week which can affect the shrimps metabolism, but it sounds like you are using a heater so that may not be a variable in this case.  

3. You added 2 new shrimp to the tank which may have carried a disease and you didn't notice it and it may have spread to the other shrimp.

4. The water company may have changed something in the tap water as I heard this occurs in certain locations during seasonal changes. And if you are using heated water from the tap during water changes heat it can cause toxic metals to leach from your pipes. Also how big was the water change and how frequently do you do them?

5. Your shrimp may be fine and the death may be unrelated to the overall health of the tank as sometimes shrimp just like to sit there, just keep observing the tank. If you experience another death soon that is probably a sign that something is wrong, but what it may be is honestly quite variable; aside from the factors above I don''t know what it may be.

 

Here are some other tips regarding the food issues. Because you have so few shrimp within the tank they may be living off the biofilm within the tanks and not require supplementary feedings, especially as the temperature has decreased recently (I'm assuming you are within the U.S) dropping their metabolism. If you feel like it you can probably try feeding them again in a 3-4 day period and if they reject it again, but are active and foraging you should be fine. Just remove the excess food to prevent ammonia spikes and clouding of the water especially if the food given was a piece of vegetable. Also it is currently winter time so the cherries may or may not breed, from my knowledge it is quite variable to whether they breed or not in the winter; a lot of shrimp keepers have non breeding shrimp in the winter, for some apparent reason I'm not one of them so it is definitely quite possible. Some other things to keep in mind a pH spike within the tank. For the longest time whenever I did a water change on my cherry shrimp tanks I would always always lose 1-2 shrimp no matter what. The problem I found out eventually is that the water in the actual shrimp tank acidified to around 6.5 or 6 somehow, so whenever I changed the water with 7.6 pH mineralized water, whether it was 10% or 25% or 50% it would cause a pH spike which would cause the shrimp to either stand still doing nothing or in go into a frenzy and try to escape the aquarium. So its just something to keep in mind when doing water changes. I hoped I helped with this post and I hope your shrimp fare better in the next few days. 

 

[Human Shrimp]

The water was originally at a temperature of 74-76 F depending on night and day, I removed the heater to lower the temperature, I imagine it took around an hour or two for it to drop now that it's winter and -14 Celsius outside (I'm in Canada.) The other two shrimp seem in perfect health, they are much more lively than the others, they are grazing a bunch and are the only ones eating the supplementary food, even if it's brief. In regards to the water change, I did a change of around 20%. I do normally a 30-40% water change every two weeks as I heard larger water changes that are more spaced can help prevent old tank syndrome.

In other news, it seems removing the ugly cluster of moss has increased their activity, they move around a little more than before, which isn't saying much but I imagine it's an improvement. As long as everything remains on track I will add the wood, I'll just float it longer and change its water to reduce the tannin which I believe will lower the affect on the pH levels. Thank you for the help so far!

[Human Shrimp]

Also the two new shrimp were added after this behaviour began, I had the idea that increasing the size might entice them to move a little more, it was also for mating because the LFS will rarely give males so I spent ten minutes with an employee spotting males.

[Revaria]

Well your plan sounds good plan, just keep in mind that changes in temperature more than 2-3 degrees at once can be stressful to shrimp and fish. As for the tannins from the wood if you do a 30-40% water change every 2 weeks I do not think your pH will get altered much or at all as you will be removing most of those tannins, especially if its a small piece of wood. Some other things to keep in mind are that shrimp don't produce that much waste, so a 30-40% water change may be a bit much. If you plan to feed them less now that its colder, changing too much water may cause you to needlessly waste remineralizing salts which are expensive, but that is my opinion if it works for you and you want to keep doing so feel free too. Old tank syndrome also takes around a few year to actually occur and is mitigated by water changes in general, so as long as you don't let the water stew for months at a time you should be good, in fact I would say from experience a newly set up tank actually takes 6 months to a year to fully stabilize. And if you are planning to breed the shrimp having more females is always better lol a 1:3 male to female ration is always welcomed in my  fish/shrimp room. 

[Human Shrimp]

Thank you for the help, I believed I bought two males for five females, but after a closer look one of them is just a really young female, so I've got 1 male and five females. The shrimp suddenly sprang to life it seems sometime last night as I woke up this morning to find most of the grazing on the moss or the substrate. Thanks again for your help!