• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

Blue cherry shrimp disappearing / dying

Joined
3 Jan 2016
Messages
383
Location
Woking, UK
Hoping someone can tell me what I've done wrong, and why my blue cherry shrimp seem to have suddenly died.

I started setting up my 25 litre nano tank at the end of November, and cycled it by using ammonia. By late December, the tank seemed fully cycled (ammonia would disappear within a few hours) and I planted my plants (HC, Glosso, hair grass, Pogostemon erectus, crypt wendtii brown, Anubias nana 'mini', and some sprigs of hornwort taken from the pond). I started doing large 80% water changes every couple of days to reduce the high nitrate level that had built up during cycling.

Just over a week ago (8th Jan) I added the first livestock: 3 otocinclus, 9 blue cherry shrimp and 1 chili rasbora (I ordered 8 rasboras but sadly 7 were DOA and have been refunded). I found a shop a few days later that had chili rasboras so added 6 more, so I now have 7. I also added a single bamboo shrimp.

Everything seemed fine, although I decided that the 9 shrimp were rather 'lost' in the tank. So on Friday (15th Jan) I drove up to Sharnbrook Shrimp and bought a dozen of their blue velvet shrimp. I acclimatised them over a couple of hours by transferring a few tablespoons of tank water ever 15 minutes or so. After releasing, the shrimps all seemed okay for the rest of the day.

When I got up on Saturday morning, the shrimps seemed to have largely vanished. I did a 30% water change and some general cleaning, and when the lights went on the shrimps were conspicuous by their absence - it was very difficult to find any, although I did find a dead one that had gone pink. I found another dead one this morning (Sun), but can't see a mass of dead bodies. There should now be about 20 of them in there, but I have to search to find any. Shortly after adding the new shrimps, they were quite prominent and occasionally cruising around the tank, but now I can only see one or two lurking amongst the Glosso.

It's worth saying that the bamboo shrimp has permanently hidden itself since it was added, and has never even opened its fans, let alone engaged in normal filter-feeding behaviour. I am concerned for its survival.

Someone advised me yesterday that my tank temperature (25°C) was on the upper limit, so I've reduced to 23°C. I use a mixture of rainwater and tapwater to give KH 4° and GH 6°. I treat new water with Tetra Aquasafe.

Some details of my setup:

Tank size: 25 litres, but probably only 20 litres of water.
Filter: Eheim 2211 external canister, rated at 300 litres per hour I believe. Water returned by Lilly pipe and seems to give good circulation.
Heater: Hydor external inline, set to 25°C but now reduced to 23°C.
CO2: Pressurised, with inline diffuser. Drop checker is permanently green. Good 'mist' while lights are on, and oxygen bubbles rising from HC and Glosso.
NH3/NH4: 0
NO2: 0
NO3: about 20 mg/l
KH: 4°
GH: 6°
pH: 6.5
Fert: TNC complete

So what's gone wrong? Why have all the shrimp, including the first batch, done a disappearing act overnight?
  • Are they simply hiding?
  • Have I stocked with shrimp too early?
  • Poisoning? Copper? I certainly haven't used anything with copper, and the plants have had lots of water changes since being planted.
  • Could there be something in either my tapwater or the water from my rainwater butt causing problems?
  • Are my water parameters unsuitable? Was that person right about the temperature?
Any thoughts gratefully received. I thought these shrimp were supposed to be fairly straightforward to keep! I will obviously be watching my ammonia level carefully over the next few days.

By the way, I know that my 200W heater is way overpowered for the tank, so to eliminate the risk of it sticking on I will be installing an STC-1000 temperature controller. Waiting for that to arrive.
 
Last edited:
I've kept cherries for a few years now and am certainly not an expert, so can only suggest the simplest thing I don't see you mention, the intake. Given the way you seem to have planned i'm sure you already have a guard on the intake but its very common for shrimps to get sucked into the filter.

Temperature wise your 25c is the upper limit for them and they prefer slightly cooler water if possible but i'd also consider the temperature change during shipping. Obviously not a problem for those from sharnbrook but shipping sounded rough enough to kill the rasboras and you maybe see a delayed reaction.

My other thought and possibly most seen problem you have already thought off when you say lots of water changes since the plants went in.

I would say though that shrimp are expert hiders and not being able to see them can be common in a new environment, especially when fish are present (even ones unlikely to do any damage) as they are the bottom of the food chain and pretty tasty. So if you don't find anymore bodies I would just give it some time and perhaps feed in a corner near the front to entice them out. Or contact the suppliers and see if thy have ha any problems with the batch. They maybe recently imported and mortalities can be high.
 
Ooh, one more thing to add...

I had a small, localised outbreak of BGA (Cyanobacteria) on the HC, so I tried squirting it with a couple of millilitres of 3% hydrogen peroxide. My instinct is that this is unlikely to be the cause, since the dose was so small and it will break down into water and oxygen. This does seem to have put the brakes on it, but it's a little early to tell. I have also slightly adjusted the angle of the Lilly pipe in case there was a local dead spot.
 
I've kept cherries for a few years now and am certainly not an expert, so can only suggest the simplest thing I don't see you mention, the intake. Given the way you seem to have planned i'm sure you already have a guard on the intake but its very common for shrimps to get sucked into the filter.
Good point. I confess I didn't have a guard on the glass siphon pick-up, but I've now wrapped some netting around it.

Part of the maintenance I did yesterday was to open up the filter, squeeze out the sponges and 'sloosh' the bio media. I checked the water in the filter, and I did find what looked like a baby shrimp swimming around, so I netted it and transferred it back into the tank. (At least I think I did; my eyesight is getting a bit rubbish these days!)

My instinct is that adults wouldn't have got sucked up, but who knows? And if they did, I reckon they'd survive in the bottom of the filter, clinging onto the sponge.

I guess you could be right; they might be hiding, and the two bodies I've seen are just random losses.
 
It's quite likely they are hiding up as there are fish in the tank.
You could try dropping a small bit of food in after lights out,wait for a while then switch the lights on to see if they've come out :)
They can be very sensitive to differences in water parameters so they are better off drip acclimatised when you first get them,did you check the tds etc of the water they came in?
I just use a piece of airline and tie a knot in it as tight as required to achieve the desired drip rate until the water in the bag matches the water in the tank.
 
Ah, okay - didn't realise they were that shy. Can't imagine the tiny chillies are scaring them, but the three otos are comparatively boisterous I guess. I had read that otos and chillies make good tank mates for shrimps.

Would nerves be the reason why the bamboo shrimp hasn't opened his fans?

To be honest, I couldn't be bothered to set up a drip line, so just did it by periodically transferring a tablespoon or two of water into their bag, which is how I acclimatise all new additions. Haven't got a TDS meter.
 
Bamboo shrimp can be tricky to feed especially in a new tank,they're really best added to a mature tank.
They need to be able to sit somewhere directly in the outflow so they can feed with their fans and it may be possible there just isn't the food available for it.
While the fish you have are suited as tank mates for shrimp,there isn't a lot of room in the tank so it's likely the oto's are frightening them and to be honest the tank is too small for oto's.
 
The otos seem very happy and active. They attack pieces of algae wafer with gusto, and they are pooing fairly regularly which implies that they're getting enough to eat. I also put blanched spinach leaves in a few days ago which they seemed to enjoy. I personally think the tank is big enough for them provided I feed them - they obviously won't find enough naturally-occurring algae, especially once the early algal blooms have reduced.

There is a branch of wood that points up towards the lily pipe and would make an excellent perch for the bamboo shrimp. I've been doing lots of reading today and I have found people saying that bamboos can take a week or two to settle in.

This afternoon I am slightly less despondent about the blue shrimps. Although I have picked out another dead one today (that's 3 so far), I have also seen 8 simultaneously - including several that were lurking deep in the Glosso carpet where they seemed to be eating something or other. It is entirely possible that many others are out of sight at the base of plants or hidden in the HC carpet - perhaps the bloom of brown diatom algae that has been plaguing the tank is actually giving the shrimps a plentiful supply of food in places where I can't see them, and maybe once that food source becomes less abundant they'll start to come out and search for food more widely.

I have also today seen a small blue shrimp almost elbowing an oto out of the way to claim its place on an algae wafer, so they don't all seem to be afraid of the otos!

I now feel that it's not quite the disaster I had been fearing when I posted this morning. Maybe in fact there's nothing wrong, and the few bodies I've picked out are due to my clumsy acclimatisation procedure. Many thanks for the advice (and I'm still keen to hear more!) and I'll keep the thread updated.
 
You mention a pink shrimp in the first post, so definitely a dead one. Are the others you have pulled out the same? or could they just be shed's which are common within a day or two of moving.
My cherrys went through a phase of hiding when they first went in, which is probably as you say, more that they find food out of the way. Saying it though when I added fish they went back into hiding for a while but now happily push the cory's out the way for food.
 
Yes one has to remember that blue cherries are more sensitive than the garden variety. My experience with yellow cherry shrimp has been similar.
 
You mention a pink shrimp in the first post, so definitely a dead one. Are the others you have pulled out the same? or could they just be shed's which are common within a day or two of moving.
Yes, all three had gone pink, either completely or partially. I'm mindful that an immobile shrimp might simply be molting, so I only remove them when I become sure they're dead. I did find one or two cast-offs during the week after the first batch of shrimps went in, and they're colourless, empty and extremely delicate. If shedding is a common reaction to moving, maybe that explains why they've all hidden away - perhaps they'll be back out soon with fresh new shells.

Yes one has to remember that blue cherries are more sensitive than the garden variety. My experience with yellow cherry shrimp has been similar.
Yes, I think I've read somewhere that the blues are more heavily in-bred than the reds, and may therefore be less robust. Perhaps the same is true of the yellows.
 
Picked another dead shrimp out yesterday morning. :(

So I decided to do a fairly large water change. Nitrates are still a touch on the high side at about 30 mg/l, and I've read that Neocaridina shrimp can be sensitive to it. Is that right - are they really that sensitive to a nitrate level as moderate as 30? Or do you consider 30 to be high? The tapwater measures about 20 mg/l, which isn't too bad - and anyway I'm diluting the tapwater with rainwater in the ratio of 1:3, so the nitrate should be much lower.

Tank pH was about 6.5, KH had fallen slightly to 3°, and likewise GH had fallen to 4.5° - the latter being close to the lower limit for shrimp, I believe. Perhaps the plants are using the GH salts, and I believe nitrifying bacteria use carbonates. Ammonia and nitrite still undetectable by my test strips.

Anyway, after a two-thirds water change the nitrate was more like 20 or maybe a little lower, KH 4° and GH 5°. pH inevitably rises slightly to about 7.0 after a big water change with CO2-depleted water. I'd still like to bring that GH up to 6°, and might buy some Epsom salts to achieve that with Magnesium to complement the Calcium hardness in the tapwater - I understand that tapwater in this country is rather low in Mg.

To be honest, my chili rasboras have never really looked happy and relaxed, and are disappointingly pale. They've been in the tank for 9 days now and should surely have settled by now. And last night after the water change they were particularly restless, swimming frantically up and down the glass as if trying to escape the tank. They didn't seem to eat much either. So I'm now wondering if there's something wrong with the water I'm using during water changes. It seems unlikely that there's something amiss with the tapwater (and I'm conditioning with Tetra Aquasafe), so I'm starting to wonder if there's something in the rainwater that is causing problems to all the fish and shrimps, but cannot be detected by the tests I'm doing - perhaps atmospheric pollutants, or maybe contamination from my roof? I use the rainwater to top up my wildlife pond in summer, and that seems healthy with newts + larvae, frogs + tadpoles, dragonfly/damselfly nymphs etc.

Today I'm considering buying a drum of RO water and doing another two-thirds water change, this time using RO instead of rainwater in the same proportion with tapwater. What do you think? Should I actually use 100% RO and try to remineralise it to the same KH/GH?

There is definitely something wrong: my blue velvet shrimps are dropping like flies, my chili rasboras are restless and pale, and my bamboo shrimp continues to sulk. I've never experienced anything like it; I'm not an inexperienced aquarist! What on earth am I doing wrong?
 
Last edited:
If in doubt, I always dose a full tank dose of PRIME. Are there any things in the tank that could be releasing something? Maybe too much CO2?
 
I've never used Prime; I use Aquasafe simply because it's what I've always used, which isn't in itself a powerful argument!

Looking at the description of Prime it does sound like a good product, so perhaps it's time I switched conditioner and used that instead. I'll have a look and see if I can find it locally, and order from Amazon if not.

Not sure if Maidenhead Aquatics sell it, and it's hard to find an aquatic shop that isn't a branch of MA, in much the same way that it's hard to find a garden centre that isn't a Wyevale. My local branch of MA is in the Woking branch of Wyevale!

CO2, well my drop checker is light green. As it happens I did tweak my bubble rate down a fraction last night, so we'll see what happens. But the chillies' behaviour doesn't fit with CO2 overdose, which I believe would cause lethargy.
 
Hi all,
I use the rainwater to top up my wildlife pond in summer
I use a <"Daphnia bioassay"> to test my rain-water. I seed the water butts with Daphnia and then when I draw the water off, basically if it has Daphnia present I know it is OK to use, and if there aren't any it isn't, and I need to clean the butt.
To be honest, my chili rasboras have never really looked happy and relaxed, and are disappointingly pale. They've been in the tank for 9 days now and should surely have settled by now. And last night after the water change they were particularly restless, swimming frantically up and down the glass as if trying to escape the tank.
I would be concerned by this as well.

Despite the test kit results it maybe a response to ammonia (NH3), if the new water is raising the pH above pH7? and the community of nitrifying bacteria/archaea in the filter haven't stabilised after the initial "cycling". If you have a high plant mass, with some emergents or floaters, you can probably excluded this as an option.

I think "Prime", or other conditioner incorporating EDTA, would be a good idea. I'm not tap water user, and we don't know exactly how <"Prime works">, but you could assume the mechanism is similar to "Amquel", which has a patent.

In "Amquel" the active ingredients are sodium hydroxymethanesulfonate (or similar) and EDTA. The EDTA chelates any heavy metals (as long as Fe ions aren't present in large amounts) and the hydroxymethane - end of the molecule reacts with ammonia to form a non-toxic, stable water-soluble compound "aminomethanesulfonate". The sulfonate end of the molecule reacts with both free-available chlorine, and combined-available chlorine in chloramines. Any ammonia (from the break down of the chloramine) is then mopped up by the sodium hydroxymethanesulfonate.

I'd also add some <"dead leaves"> to the tank. Some DOM will act as a chelator, and helps the growth of micro-organisms for both shrimps and micro Raspbora.
They didn't seem to eat much either.
I'd be tempted to try some micro-worms, they are very low maintenance to keep, and elicit a feeding response in most fish.

cheers Darrel
 
Last edited:
I agree with Darrel. I live in Wiltshire and Ive used tap water most of the time. Ive never been able to keep shrimp alive for long periods and fish also eventually die. I dont use prime so Im thinking of getting some. Also the water here is very hard so I dont think you can get much worse.
 
Thanks chaps. I couldn't find Seachem Prime to buy today, but have ordered some and will give a whole-tank dose when it arrives. Mind you, it's so concentrated I will find it hard to dose anything less than a whole-tank dose of 20 litres, which requires just one millilitre of Prime - good job I bought some syringes for measuring tiny quantities.

I bought a drum of RO water and have done another two-thirds water change today using 9 litres of RO and 3 litres of tapwater. Just giving the fish a 'chill-out' period with the lights off to calm down. I've also decided to plug one of my lights into the same timer as the CO2, so that it comes on early and goes off early, thus giving me a ramp-up and ramp-down to the photo period. I do have quite a lot of light - about 2000 lumens of LED which is more-or-less equivalent to 4 Watts per gallon of T5.

And I bought some Epsom salt and used the recommendation that I read somewhere (possibly on these forums) to dose 44 mg per litre for a 1 degree GH rise. Made a stock solution of 44 g in a litre, then dosed the tank with 20 ml of that solution. And as if by magic, my GH has gone from 5 to 6. It's nice when things work out properly, isn't it?!

Let's see whether the chili rasboras er, chill out a bit. And whether my shrimps stop dying. And whether my bamboo shrimp stops sulking.
 
The Seachem Prime arrived this morning, so I have dosed.

Also, just noticed that one of my remaining shrimp is carrying eggs, so it's not all bad news.
 
Back
Top