Cherry shrimp dying off gradually

[Anomander]

Hello all, before I describe the issue, here are my parameters:
1. 60ish litre tank
2. Setup is nearly 7 months old
3. Two sponges (30 ppi & 20ppi) attached to powerheads at opposite corners of tank, one with venturi and duckbill pointed towards surface.
4. 8hrs light via Ciano LEzdCLA60 (8W – 18VDC);
5. Fine Unipac silver sand substrate
6. Low tech
7. Temp 25c
8. Per week: 6ml TNC Complete, 0.8ml TNC iron, 1.6g Epsom Salts
9. 10% WC per week with light vacuuming of accumulated waste on substrate.
10. Anubias, Java Fern, Water Sprite, and Salvinia planted at initial setup
11. Cherry shrimp, no other livestock

About 4 months ago (so when the tank was 3 months old) I purchased 8 Cherry Shrimp. After a month they started breeding, and this has continued to the point where I could count at least 50 or so shrimplets/juveniles. However, over the past 9-10 days I have had 4 adult shrimp die (none on the same day). There is not sign of fungus or failed molting.

One of these shrimp was barely alive when I found it. It was still for a while, then it would try and move but had trouble keeping upright. It looked like it had some kind of small injury (almost like a small squarish piece of its shell was missing from its side with the white tissue showing through) and other shrimp were trying to eat it. None of the other dead shrimp have shown this injury, but at this point I thought food might be the issue due to the other shrimps trying to eat this dying one.

Before the first babies arrived I had tried feeding Glasgarten Shrimp Dinner 2 in a feeding dish, but only a couple of the adult shrimps seemed only vaguely interested, so I took that as a sign there was enough biofilm etc, especially once the breeding started, so I stopped feeding. Once the babies started arriving I was feeding Glasgarten Shrimp Baby once every few days. About a week ago, after the second Shrimp death (this being the one described above) I decided to start feeding more. I've been rotating between Shrimp Dinner 2 (in a dish) and Shrimp Baby on alternate days. The shrimps seem very interested in the Shrimp Dinner, and there is usually a collection of adults and juveniles and smaller shrimplets in the dish and squabbling over it. I remove the dish after 3 hours.

I have also added two aldar cones and a Catappa leaf a few days ago. However, I was disheartened to find a fourth dead shrimp today. I have not tested my water parameters due to the advice that test kits are unreliable. My plants all seem fine; my Salvinia is growing voraciously and is very green. My Java Fern is showing new growth at the tips. I have not changed anything about my routine (water changes etc) in the past few weeks.

Any help would be greatly appreciated, I'm happy to provide any more info I may have missed.

E2A: Sorry I posted before finishing my post

 

[Little]

Is it possible someone in the family has used some kind of spray in the room?
Deoderants or cleaning products perhaps?

 

[Anomander]

Is it possible someone in the family has used some kind of spray in the room?
Deoderants or cleaning products perhaps?

Hi there, thanks for your reply. It's just me and my partner and we've always been very careful about those sort of things. The only thing I did do a couple of weeks ago was spray a bit of white vinegar in the bottom corner of the wall behind the tank, but this was sprayed directly onto the wall and the spot was about 3-4 feet below the top of the tank, which is lidded apart from a small opening for feeding.

 

[Andy Pierce]

We need to know your water KH and GH parameters. If you're using tap water these should be available in a report from your water company. There are some requirements for cherry shrimp both in terms of KH (alkalinity, relates to pH) and to GH (particularly calcium). I don't see that you have a calcium source in your ferts and that will be needed by the shrimp.

 

[Anomander]

We need to know your water KH and GH parameters. If you're using tap water these should be available in a report from your water company. There are some requirements for cherry shrimp both in terms of KH (alkalinity, relates to pH) and to GH (particularly calcium). I don't see that you have a calcium source in your ferts and that will be needed by the shrimp.

Hi there, I live in North London so the water is quite hard. I've attached the Water Quality Report. It says my total hardness as CaCO3 is a mean value of 265 mg/l. E2A: The Alkalinity as CaCO3 is a mean value of 201 mg/l.

 

[Anomander]

Is it possible someone in the family has used some kind of spray in the room?
Deoderants or cleaning products perhaps?

This got me thinking - would it be possible that I didn't rinse my hands of moisturiser or soap enough on one occasion before putting them in the tank? Again I'm usually very careful with these things and I can't actually recall such an occasion, but I'm stumped otherwise.

 

[Andy Pierce]

Hi there, I live in North London so the water is quite hard. I've attached the Water Quality Report. It says my total hardness as CaCO3 is a mean value of 265 mg/l. E2A: The Alkalinity as CaCO3 is a mean value of 201 mg/l.

Cherry shrimp will do ok in this water, but maybe not great. The pH is going to be a little high for their taste so they might not breed well (or maybe not at all) but it doesn't explain sudden deaths. You're good for calcium levels.

 

[Little]

This got me thinking - would it be possible that I didn't rinse my hands of moisturiser or soap enough on one occasion before putting them in the tank? Again I'm usually very careful with these things and I can't actually recall such an occasion, but I'm stumped otherwise.

I was more thinking of something that could have had something like copper or bleach in it. I don’t think soap or hand moisturiser would have been an issue.

 

[mlgt]

Let me know if you want more cherry. Im in N2

 

[Anomander]

Let me know if you want more cherry. Im in N2

That's very kind, thank you

 

[Maf 2500]

I'd be tempted to change more water. At 10% per week stuff can build up in the water. The minerals and ferts you are adding seem to be in sensible amounts so it is very unlikely anything has built up to harmful levels. However, at that water change rate any element or compound not used up by plants or natural biological processes will, after a few months, stabilise at 10 times the initial dosage level. Like I said, unlikely, but for peace of mind I would change more water.

 

[Anomander]

I'd be tempted to change more water. At 10% per week stuff can build up in the water. The minerals and ferts you are adding seem to be in sensible amounts so it is very unlikely anything has built up to harmful levels. However, at that water change rate any element or compound not used up by plants or natural biological processes will, after a few months, stabilise at 10 times the initial dosage level. Like I said, unlikely, but for peace of mind I would change more water.

Thanks Maf. Maybe I'll try 25% a week - I've always been cautious with the WC amount as there seems to be a lot of opinion out there which leans towards minimal water changes for shrimp tanks.

 

[tam]

Do you have other pets that you treat for worms/fleas? Although if it was a contaminant, I think you'd probably see higher deaths over a shorter period.

 

[Miniandy]

+1 on the change slightly more water. The no water change thing is more to do with caridina (bee) shrimp. 25% is enough, but I'd do a couple a week for a couple of weeks to get going.

Can we get a pic of the tank?

I'd also be inclined to get some activated carbon to remove any possible contaminates. A small bag in there for a couple of weeks will help.

Another, probably, unrelated thing - If the shrimp are still feeding after 3hrs on the food, I'd be inclined to leave it. Only remove if they've lost interest.

 

[Anomander]

Do you have other pets that you treat for worms/fleas? Although if it was a contaminant, I think you'd probably see higher deaths over a shorter period.

No, no other pets apart from the Shrimp. And yes, the deaths have averaged out as one every 3 days

 

[Anomander]

+1 on the change slightly more water. The no water change thing is more to do with caridina (bee) shrimp. 25% is enough, but I'd do a couple a week for a couple of weeks to get going.

Can we get a pic of the tank?

I'd also be inclined to get some activated carbon to remove any possible contaminates. A small bag in there for a couple of weeks will help.

Another, probably, unrelated thing - If the shrimp are still feeding after 3hrs on the food, I'd be inclined to leave it. Only remove if they've lost interest.

Thank you, I will increase the WC schedule. I will get a picture once the lights come on. I'll also look for some activated carbon online, and good to know about the food; the company says it stays stable in the water for a while. Thanks for all the advice.

 

[mlgt]

What about the food you feed them? Has that gone off or exposed to something perhaps? Its likely to be some form of contamination. But it shouldnt be dying off. 60 litre is plenty of water column to not cause some sort of die off.
Even if you didnt do the weekly water changes I am sure many will say they will be fine with just a top up now and then unless your population is really booming and we talking about hundreds of shrimp in the 60l tank.

I have 2 54/60l tanks at home one with cherry,orange shrimp and another with blue diamonds both have fish in the tank and rarely get any losses. Plus they shrimps will eat each other 🙂

 

[Anomander]

What about the food you feed them? Has that gone off or exposed to something perhaps? Its likely to be some form of contamination. But it shouldnt be dying off. 60 litre is plenty of water column to not cause some sort of die off.
Even if you didnt do the weekly water changes I am sure many will say they will be fine with just a top up now and then unless your population is really booming and we talking about hundreds of shrimp in the 60l tank.

I have 2 54/60l tanks at home one with cherry,orange shrimp and another with blue diamonds both have fish in the tank and rarely get any losses. Plus they shrimps will eat each other 🙂

Thank you for the information. Both foods are made by a reputable company and are in date, plus they're always kept in their original lidded and sealed containers. I think I'll try the increased water changes unless they'll do more harm than good to the shrimp.

 

[mlgt]

No, no other pets apart from the Shrimp. And yes, the deaths have averaged out as one every 3 days

What about the substrate? Any air pockets? Perhaps temp is higher than needed for cherry? I have kept them in various temps from no heater, but find that 22-24 is totally fine. When you do water changes are you measuring the temp of the water you put in too?

 

[Anomander]

What about the substrate? Any air pockets? Perhaps temp is higher than needed for cherry? I have kept them in various temps from no heater, but find that 22-24 is totally fine. When you do water changes are you measuring the temp of the water you put in too?

I can't see any 9bvious air pockets, though I'm not sure what they would look like. I check the temp of the water change water with a thermometer so it matches. I could try turning down the heater but it's a bit difficult to get it to the temp I want.