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Giving Up on Shrimp (or maybe not?)

John S

Member
Joined
13 Dec 2008
Messages
849
Location
Welwyn Garden City
A while ago I set up a 35L tank that housed about 50 cherry shrimp. It had used florabase as a substrate, some manzi, stems and moss. Its Co2 injected with lean EI ferts.

At first there was always berried shrimp although few babies survived. The other tank inhabitants were 6 Ottos. Over the last 3 months the numbers really tailed off and I now only have a handful.

I recently got a TDS meter. My TDS from the tap is 350 but by water change time the tank is at 795! Is the die off due to the high TDS? I'm in Hertfordshire with concrete water.

Any ideas or suggestions as I'm about to give this up as a bad job.
 
That doesn't sound good. Something must be pushing the TDS up. We're going to need a bit more info to get to the bottom of it though.

How often are your water changes?
How much water do you change?
When you say lean EI, how much exactly are you dosing?
What filter are you using?
How often do you clean your filter?
Have you checked your filter for any blockages lately?
 
Thanks for the reply.

I change water weekly.
I change about 30% by preparing 10L the night before the change.
I dose 5ml of macro twice per week (no micro)
I'm using and Eheim 2213 with sponge and ceramic noodles as media
The filter is cleaned (rinsed in tank water) about once a month
All filter pipes were cleaned out last week and the impellor housing cleaned
 
Hi John,
Firstly, your high TDS is probably due to a very high bioload in the tank - I think 50 Cherries for a 35 litle is quite a lot - and the Ottos bring it even higher.... One other thing - please be easy on me with this one as it is not 100% confirnmed - CO2 injection is thought to hinder the production of offspring by dwarf shrimps (I am guessing that Cherries are included). Depending on what kind of stems you have and lighting, you may be able to ditch the CO2 (decreasing the lighting) and rehome the ottos.
Then I would go with gradual change of the TDS by doing small water changes often and little volumes. I would also reconsider the EI dosing (maybe making it all even leaner? - all depends on what stems you have).
As far as I know, Cherries are O.K. with TDS as high as yours but do not withstand anything higher than 500... Your TDS is clearly from an organic matter so reducing the bioload is the way to go, I think...
As you probably know without me telling you - the moss is fine in low light and low fert/no CO2 tanks...
There might be a bacterial infection in your shrimps but to determine that, the other "bad" factors should be eliminated...
 
Hi again John,
Whils I was typing, some more posts came through - you say you "prepare 10 L the night before" the water change... What do you mean? Just standing the water is not good enough! You NEED to use a dechlorinator (and specifically the ones which neutrolize heavy metals) - if you just "stand" water in a bucket, you are killing your shrimps by all those chemicals in the tap water...
 
Hi John
How much Macro/Trace are you dosing?
I would stop dosing ferts as a test....try just water changes,small ones over the next month or two.
Try and get TDS down to tap water TDS
What colour is the Co2 drop checker?
What stems do you have?
Do you have a heater?
hoggie
 
Hi Nat,
I can rehome the Ottos and move the stems out into another tank. Yes, I must admit I was wary about CO2 injection with shrimps but there seemed plenty of evidence to say that it should be OK. I will take your suggestions and knock off the Co2, perform little and frequent water changes and monitor the TDS.
 
Hi John
How much Macro/Trace are you dosing?
I would stop dosing ferts as a test....try just water changes,small ones over the next month or two.
Try and get TDS down to tap water TDS
What colour is the Co2 drop checker?
What stems do you have?
Do you have a heater?
hoggie

Hi Hoggie,
I was dosing 10ml macro per week with no micro.
DC is green, not lime green.
Tank has a heater and runs at about 21 degrees
 
Hi again John,
Whils I was typing, some more posts came through - you say you "prepare 10 L the night before" the water change... What do you mean? Just standing the water is not good enough! You NEED to use a dechlorinator (and specifically the ones which neutrolize heavy metals) - if you just "stand" water in a bucket, you are killing your shrimps by all those chemicals in the tap water...

The water is dechlorinated with Seachem Prime and left in the same room as the tank.
 
Hi John
I think the TDS could be the problem.
Leave off the fert dosing as i mentioned....3 to 4 small water changes a week would be a start.
You could use RO water to reduce the tank TDS if available.
hoggie
 
The water is dechlorinated with Seachem Prime and left in the same room as the tank.
Oh, that's good - it is just sooo many people still think that "standing the water overnight" is going to make it suitable for a water change...
I do not really know IF the injection of CO2 affects dwarf shrimps breeding but my shrimps tanks are kept either without the CO2 or with a very-very-very lean dose... That worked for me... Also, thinking about Macros - with your tap water TDS I am sure there are enough Macros (and Micros!) in there to maintain the moss (and some left!) and depending on the type of your stems, the water content may be more than enough for them as well... So, I am joining the opinion of stopping the Macros altogether for the time being to see what results this will bring...
 
I recently got a TDS meter. My TDS from the tap is 350 but by water change time the tank is at 795! Is the die off due to the high TDS? I'm in Hertfordshire with concrete water.

My cherry shrimp wouldn't breed in such a high TDS, so the high TDS maybe a concern but the problem is what causes it because the contstant fluctuation from 350 to 795 and back during a water change can't be good either on shrimp or fish.
There are some good points made about the high bioload. 6 ottos in a 35L tank and so many shrimp just can't be good long term. The tank is too small for ottos. Have you seen the shape of these fish. They are like an aeroplane :) and will feel way better in bigger tanks, more chance of getting enough food too.
On another note, I have personally kept 100-ish srhimp and 9 grown up corys in a 54L tank without any deaths/problems for months(my fault but now fixed the situation), without a rising TDS so there's a chance you've got another reason for such TDS fluctuation. What's the type of substrate? Or do you have stones of some kind that maybe releasing calcium/magnesium or other minerals?
As some people already mentioned, if someone keeps shrimp for the first time, I'd recommend a fully low tech tank. Once you keep them for a few months, if they are ok, they'll breed like snails. Once you are sure how to keep them, then start experimenting with dosing, CO2 and TDS. Shrimp are more sensitive to such conditions for some reason.

Seachem Prime...Im not that keen on this product....because of the smell.
Just wondering could there be a related issue with this product?
hoggie

I wouldn't think Prime would be the cause of the problem. I use it in all my tanks, including the ones with shrimp.
 
An Eheim 2213 for a 35l tank is more than enough filtration. Cherry shrimps have a very small bio load so I doubt that is contributing to the really high TDS.

I switched to using Seachem Prime after reading about when I wanted to start keeping cherry shrimps. It appears to be used successfully by quite a few shrimp keepers out there. Although I do agree that the smell is off-putting.

It could be that your EI hasn't been lean enough and the levels in the tank have been creeping up over time. My cherry shrimps have no problem with 50% water changes, provided I match the temperature. But then there is not so much difference between my tank and tap water TDS. I also stand my water for 24 hours and find that the TDS of the tap water drops during that time.

You could get the TDS down with lots of small water changes as above. I just had another thought though. What if you took all the fish and shrimps out, emptied and refilled the tank and then re-introduced the fish and shrimps as if you were moving them to a new tank? Obviously you would need to drip-acclimatise the shrimps and it would take a while catching them all in the first place! Then continue with your EI dosing but do 50% weekly water changes. That way you could be sure that the nutrient levels would be reset each week and not climb. Otherwise it could take days if not weeks to get your TDS down that much. I don't know what anyone else's thoughts are on doing it this way?

Another thing: Do you have a shrimp guard on the filter intake? Have you checked in there for baby shrimps? My filter is full of baby shrimps!
 
Thanks to everyone for their responses:

There are some good points made about the high bioload. 6 ottos in a 35L tank and so many shrimp just can't be good long term. The tank is too small for ottos. Have you seen the shape of these fish. They are like an aeroplane and will feel way better in bigger tanks, more chance of getting enough food too.

Oddly enough these have done far better in this tank than in my bigger tank and feed regularly with the shrimp. Point taken though and they will be on the move this weekend.


What's the type of substrate? Or do you have stones of some kind that maybe releasing calcium/magnesium or other minerals?

Substrate is a pre used florabase. There are some small red lava rocks in the tank which I read would have no impact on TDS. I did notice last night a broken piece of manzi wood. This had gone quite soft, so maybe the decomposition of the wood is a problem?


What if you took all the fish and shrimps out, emptied and refilled the tank and then re-introduced the fish and shrimps as if you were moving them to a new tank? Obviously you would need to drip-acclimatise the shrimps and it would take a while catching them all in the first place! Then continue with your EI dosing but do 50% weekly water changes. That way you could be sure that the nutrient levels would be reset each week and not climb. Otherwise it could take days if not weeks to get your TDS down that much. I don't know what anyone else's thoughts are on doing it this way?

This did cross my mind last night. As much as I'd like to take the scientific step by step approach to find the cause, I don't want these fellas to suffer any more.
 
Hi all,
It could be that your EI hasn't been lean enough and the levels in the tank have been creeping up over time.
That is my suspicion. I'd just stop the fertilizer addition and turn the CO2 off. If your stem plants melt, just take out the melted sections.
Your TDS is clearly from an organic matter so reducing the bioload is the way to go, I think...
I think the bioload may be too high, but I don't think it is a TDS problem as such. Our tap water is about 600 microS (nearly all CaCO3) and Cherries do better in that than they do in the rain-water tanks (about 100 microS). The TDS reading isn't mainly from the organic matter, it would be higher if TDS was actually measured, but TDS is estimated from conductivity, and the non-ionic components of TDS aren't counted. The high conductivity is almost certainly from the fertiliser addition, added to the calcium carbonate content of the tap water.
You NEED to use a dechlorinator (and specifically the ones which neutrolize heavy metals) - if you just "stand" water in a bucket, you are killing your shrimps by all those chemicals in the tap water...
Prime isn't going to do any harm, and I don't use tap water myself, but I'm dubious about this one, the EU laws are really tight on heavy metals and the limits are now in the low ppb (10-9) region. Also the water is hard, and the chances of there being any HM ions present is realistically nil. You might get chloramine used as a disinfectant and PO4--- added, but in heavily planted tanks this isn't really a problem.

cheers Darrel
 
Hi John,
795 TDS is quite high, especially given that your tap water is only 350. Im guessing that your tank tds after a water change is still quite high as 30% water change with 350 tds wont drop the tank tds a huge amount, maybe around 100tds maximum? I dont think there is anything in the tank that could be effecting TDS to that degree so my guess would be a gradual build up over time, with the 30% weekly water changes not being enough to dilute it.
Personally id be aiming to keep the tds sub 450, so to implement the change i would increase your water changes to at least 2x per week, or more smaller ones as suggested above until the level is reached.....your tap water is fine so id maybe try to get the tds lower than 450, say 350-400 and then weekly 30% water changes should keep it stable without too much change over the course of a week. If you see it rising, perform extra water changes to keep it stable and look at reducing fert dosing (you may also need to lower lighting intensity).
C02 addition makes the tank high tech, so with that and fert dosing extra organic waste is produced by the plants which needs to be cleaned. Your filter removes some, but water changes the most part. Regular filter cleaning is important to prevent build up and breakdown of detrius which can add to the organic load and increase bod.
I dont know what/how often you are feeding the livestock, but im guessing to feed the ottos its a daily routine. When you start adding food daily and shrimp are feeding daily its surprising how much waste the tank produces. This combined with the by products of a high tech tank Id begin also cleaning your filter sponge as part of a weekly maintenance routine, and rinse the noodles monthly.
Keeping the tank clean is key, i have probably 200+ CRS in my 55l nano tank, fed daily (due to the numbers) and manage to keep tds stable at sub 180. I use liquid carbon and tropica fertiliser daily. I perform weekly 30% water changes and clean the filter floss and sponge at every water change....they are filthy every time! I know from my experiences with this tank that keeping the tank clean is the key to success. Drop filter maintenance or water changes and the shrimp stop breeding :)
Stick with it mate, its just a case of a couple of alterations and youll have them breeding again in no time.
Cheerio,
Ady.
 
Might be just coincidence and you will succeed in different tank.
I dont think your tds is a problem
I dont think your water changes is a problem.
Someone mentioned a bioload of shrimp which you can ignore.
CO2 is not a problem.
The best success with cherries I had was always in High tech tanks, no matter how bad I abuse the parameters.
 
And I never ever used dechlorinator in any shrimp tanks including high grade species. Do not take that as an advice though ;)
 
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