Another case of mysterious deaths

[Myola]

In the last week or so I've had 3 deaths in my cherry shrimp tank. Parameters all seem fine: pH 7.2, TDS 270, NO2  0, NO3  5, Gh 7, Kh 1, Temp 23C. But out of the blue these three deaths. I watched this evening as number 3 died right in front of me. She zipped briefly around the tank, sometimes on her side or upside down, then settled on the floor of the tank for a couple of minutes and didn't move. Then jumped up and curled herself up and fell down on her side, dead. The photo is terrible (left my good camera at work today) but I did notice a sort of gap in her shell between her carapace and her abdomen. I don't see this gap on any of my other shrimp and don't remember her having it either prior to today. I wonder if this is some sort of symptom that I could have picked up on and indicated that something was wrong. I did have to move the tank a week ago to a room with air con as the water was sitting for a couple of days at 26C. Could the high temp have had something to do with it, or would they just have died right then and there when the tank was hot? The only other recent change is the addition of an oxydator 2 weeks ago. Could it be that, or maybe a moulting issue? There is evidence of moults in the tank and I have lots breeding. There are many babies now that I have raised my GH, which was an earlier issue. If anyone has any ideas, it would be great.

[jayc]

12 hours ago, Myola said:

maybe a moulting issue?

^ This. 

It might have sustained that injury while trying to moult. Which points to water parameters.

Lower the temp of the tank in a short amount of time can induce moults. By moving the tank to a cold room, the water temps dropped quickly. Maybe she wasn't ready for a moult.

26 degC isn't (shouldn't be) a problem for Cherries.

 

The failed moult could also be a cause of GH 7.  

Are you adding any Calcium/Magnesium to the tank? Got any rocks in your tank?

GH 7 seems like a weird number with a low KH of 1 and high pH 7.2  and soft TDS of 270.

KH 1 should give you lower pH.

And GH 7 should give you higher TDS.

Unless, one or two of those measurements were not accurate.

Edited October 26, 2018 by jayc

[Myola]

Hi Jay C,

Another death overnight. Looks the same as the 3 previous deaths this week with a split in the exoskeleton between the carapace and abdomen. When we moved the tank just over a week ago, the water temp went from 26.5 to 23 in 24 hours. Would that have been too quick and cause the moults? 

I've redone all my water tests this morning with the same results except for TDS which is 285 now (creeping up because of evaporation I think). The water I'm using is tank water which is a combination of rain/bore water. Straight out of the tank it currently has a pH of 7.4 or higher, but this varies throughout the year depending on the exact make-up of the water i.e: how much rain water and how much bore. For this reason I often have to add 'API Proper pH 6.5'. I aim to make my water fairly neutral. If I feel like I'm having to add too much of this product then I will go for a pH of 7.2 so that I don't have to add too much. I try really hard to keep the water as stable as possible and do 10-15% water changes religiously every week. I feel like I'm losing the battle though and am now considering an RO system. As well as adding the pH product, I also have to add Salty Shrimp GH/KH+ to get the GH up as this is extremely low or non-existent in our water. Does all this make sense now? Any other suggestions? They have just started breeding and out of my little family of 15 adults, 5 are berried and 2 others have dropped their babies this week. So in amongst the death, there has been life too. I just hope I can work out what I'm doing wrong though and keep them alive. ?

 

[jayc]

18 hours ago, Myola said:

add 'API Proper pH 6.5'. 

This maybe causing unpredictable problems. You won't need proper pH if you used pure rain or ro water with salty shrimp GH. This probably explains your weird readings.

 

[Myola]

Thanks Jay C, no more deaths overnight thankfully. Since the deaths only started occurring when we had to start putting bore water into our water tank recently, I think it must be the pH fluctuations as you said. Right, that's it, I'm off to buy an RO system. Any recommendations? Also, what would be the upper limit for the temp range for Neos?

[jayc]

3 hours ago, Myola said:

Any recommendations?

yep,

https://www.filtersystemsaustralia.com.au/reverse-osmosis-water-filter/aquarium-systems.html

Tell them SKF sent you. And ask if they still have a 10% discount for SKF members. 

If you are confused about which tap attachment to get, ring them and talk to them.

Either the $190 or $199 is good enough. If you want to use it for drinking water too, get the $285 system. 

 

[Myola]

2 hours ago, jayc said:

 

Tell them SKF sent you. And ask if they still have a 10% discount for SKF members. 

 

Either the $190 or $199 is good enough. If you want to use it for drinking water too, get the $285 system. 

 

Decided to go ahead with the $199 system and have contacted them regarding a discount, now waiting to hear back from them (probably tomorrow I guess). Now I've just gotta work out how I'm going to justify the expense to hubby!  

Thanks so much for the help and info, what would we noobies (and our shrimpies) do without you!!??

[jayc]

3 hours ago, Myola said:

Thanks so much for the help and info, what would we noobies (and our shrimpies) do without you!!??

No problem. I get the joy of helping others in the hobby.

[Zoidburg]

If using SS GH/KH, then you should have about 3.5 KH to 7 GH.

At 0-1 KH, I would expect there to be a buffering substrate reducing the KH and lowering the pH. This is probably where the API Proper pH comes into play... and is probably wrecking havoc on your tank and inhabitants.

Cherry shrimp do not need a neutral pH and can thrive at higher pH levels.