5 RCS all dead after 2 months, not sure cause
I bought 5 Red Cherry Shrimp from a local fish store in mid-December. From day 1 I only saw 2 in the tank at any one time; I assumed most were hiding, until mid-January. That was the last time I saw 2 in the tank, and 1 died the next morning. Since then I have consistently seen 1 shrimp, usually feeding on a leaf or piece of equipment. That one died today. Now I must assume that three died close to being added, one lasted a month, one lasted two months.
This is a planted tank that was thriving 5-10 years ago; large colony of shrimp, 15 fish, snails, plants all doing well. It went through a period of neglect 5 - 2.5 years ago. For the last 2+ years Ive been working on slowly eliminating excess nitrates, bringing the PH up, slowly, so the remaining fish would survive. It had been stable for about 6 months so I decided to start adding a few fish, shrimp and plants, slowly.
The one problem that occurred during this transition was an onslaught of diatoms. I discovered my tapwater in my new location had excess silicates; changing 5 gallons every other day to get past the old-tank syndrome dumped in a ton of silca leading to massive diatom blooms. I have made progress but am still working on eradicating the ditoms.
I added the 5 shrimp and a couple snails to assist with my clean-up efforts. At this point, my plan is to get rid of the diatoms, making sure everything is stable for a couple months, then add more. But I'm honestly not sure what the root cause of the shrimp die off, and would like to hear if you think diatoms/silica is a factor. Also, although my tap water has high silicates, there isn't much dissolved silica in the tank. After a water change I add a bag of Phosguard to remove silica for 2 days. Then do a relatively high dose of phosphate for the plants. Not sure if this would negatively impact the shrimp in any way.
Additional info below.
1. Type of shrimp. Specific species if possible. About how many shrimp in tank?
Cherry red shrimp. Exactly 5.
2. How long have you had the shrimp? Where did you get them from? International Seller? Local Seller?
3. Other livestock living with the Shrimp. All of them. Any new additions since issue?
4 Dwarf neon rainbowfish, 2 corys, 2 nerite snails, 1 pond snail that snuck in on some plants and was removed
4. Size of tank.
37 gal tank
5. How long has tank been setup and cycling for?
Cycled for years. Tested for Ammonia and Nitrite many times when battling old-tank syndrome and never found any.
6. Water source. Using Tap? RO? Part tap part RO? Are you re-mineralizing the water and aging before putting in tank? How long before? Parameters/temp verified before water change? Any difference from the parameters in the tank compared to prepped water?
Tap, with high silica. I add Seachem Equilibrium at water changes
7. Water parameters:
PH 7.6 GH 9, KH 3, Ph .5, Am 0 NI 0
c. When is last time you verified all of the water parameters? Have the parameters changed lately since issue?
within the last week
only change was a major drop in N, which I accounted to the plants taking it up. I started dosing Seachem N to get to 10-20 ppm, which I generally have not done in the past.
8. Substrate. Buffering? If so what kind. How old is the substrate
Eco complete and sand. 10 years old
9. Plants? Dosing ferts? How much and how often. What kind?
Java fern and annubias form years ago. New sword, new jungle val, new micro sword, new rotala
Dose seachem N as needed, flourish 2.5mm twice a week, equilibrium at water changes, fluorish excel 2.5mm nightly.
10. Do you inject Co2, if so, est. PPM?
11. How long are lights on?
6.5 - 8 hours per day
12. Type of Filtration? Is intake blocked enough to keep shrimp from getting sucked in?
Cascade canister filter, haven't done anything to the intake
13. How often do you do maintenance on filter/s? Do you clean with tank water?
Generally every 1-2 weeks as I work on the diatoms, I do use tank water to rinse the filters
14. Do you use water conditioner? What kind?
15. What do you feed your shrimp and how often?
I don't feed the shrimp
16. Has anything changed since problem? If so what specifically changed? Has anything changed in the tanks external environment? For example: Did the roommate/ sig. other/parent, spray or apply pesticides, even in another room? Did you have house guests that vaped or smoked inside? Was any demolition work done in the house?
New additions dying within 2 months. No chemicals or construction around house.
17. Are they acting strange? Racing around the tank? Hanging out at top? Just sitting there not moving much? When did the behavior change?
Seemingly normal behavior
18. What is the issue? Please be specific as possible. How many is this happening to? How long has it been happening?
All 5 died over the course of 2 months
19. If they are dying how are they dying? Are they dying on their back? On their sides? Are they dying when molting? Are they disappearing?
On their sides, I believe. I only found 2 of the 5.
20. If possible please include as clear picture as possible.