Tank Issue/Cherry Shrimp Growth

2432 Views 29 Replies 8 Participants Last post by Navigarden, Jan 29, 2011

tamsin

Discussion Starter · Jan 13, 2011

Hiya,

I've been reading the forum quite a bit - it seems to pop up everytime a google a plant question! I have some of those but I want to get an issue I have with the other inhabitants solved before I start on them. This is a sort of half shrimp/half fish question, so I hope it's okay to put here.

I've got a 75l tank (aquaone 510) with plants

, 2 amano shrimps, 3 Kuhli, a pair of cherry barbs and a colony of cherry shrimps. It's been running about two years but I have a couple of issues.

I started with two cherry shrimps and they grew up and produced a lot of little cherry shrimps. The trouble is the offspring don't seem to be growing very big. The original two (which passed away around the 18 month mark) were about an inch or so long but the biggest youngsters (about 10 months old) are still only 1/2". They grew quite fast initially and I passed some on to my parents and sister and they grew up. They seem to be breeding despite the size and I think I currently have around 20-30 between 5mm and 1/2".

Could anyone suggest why the aren't getting full size? The water tests okay, are there too many for the tank? I don't feed them specifically but I think they eat the fish food (I have sinking pellets for the Kuhli) and they seem to spend most of their time plucking away at the javamoss and plants.

I'm not sure if/how it's related but I have a big issue with fish, any time I try to add a couple more I tend to lose half what I put in over a couple of weeks plus a couple of the existing ones. Hence, I only have 5 fish. I can't work out the cause though, the standard water tests seem fine, the shrimps aren't affected (and I thought they were more sensitive to water problems), I'm using the same water (RO) as the rest of my family and buying from the same suppliers. I haven't added any for about 6 months now. Is there anything that effects fish but not shrimps?

Sorry, the post got a bit long, but if anyone has any ideas I'd really appreciate it.

Thanks
Tam

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1 - 20 of 30 Posts

Navigarden

· #2 · Jan 13, 2011

It sounds like there is something off with your water column as both your fish and shrimp are effected. You dont sound like you are overstocking at all. I have a similar volume tank and it supports at LEAST 100 RCS (probably waay more) as well as 5 threadfins.

Can you lease post your tested water parameters? Are you just using straight RO?

Also starting just from 2 RCS you are going to have inbreeding problems. If everything checks out with your water I would cut your current population (20-30?) in half and order at least 10 more from a different supplier...

need those water parameters though.

Navigarden

· #3 · Jan 13, 2011

Do you have any problems with your fish predating your RCS?

tamsin

Discussion Starter · #4 · Jan 13, 2011

I'll do a proper test tonight and get back to you with the numbers but I just did a quick stick test and that showed:

Nitrate: 25-50
Nitrite: 0
GH: 7-14
KH 3
PH 6.8

It's RO plus the stuff you put in after making it (sorry my dad mixes it and I can't remember what it's called :icon_redf ).

The fish totally ignore the shrimps unless they drift past their noses in which case they might make a half hearted chase - I've never seen one catch one or go looking. The whole back of the tank is covered in a matt of Java moss which I presume shelters the really tiny ones until they aren't bite sized. Though saying that the ones I passed on to my parents managed to reproduce (though in much lower numbers) and that's a big community tank with no moss and all sorts of things you'd think would consider them snack sized.

Thanks
Tam

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g01ngog

· #5 · Jan 13, 2011

I think its inbreeding that is causing the problem. You started with two: mom+dad, they had kids. And... those kids had kids, which means that brothers and sisters shacked up. The genetic pool for the shrimplings is very small and the same dominate traits will be passed on.

tamsin

Discussion Starter · #6 · Jan 13, 2011

I was worried that would an issue so I added two more when they first produced offspring. I would have thought that the first generation would be okay or the cross between the the two batches. It seems a little odd that not a single one has got large when both parents were full size.

Swapping some out sounds a good idea, but I'm reluctant to buy more if there if something about the tank that's not good for them.

Do those water values sound okay? Is there something specific I should test for?

guppygolucky

· #7 · Jan 13, 2011

Inbreeding might be suspect. If you aren't feeding them specifically it could also be a problem. You have fish in there also, so a smaller shrimp can hide better from predators.
Lack of new genetic material, not feeding them (even though they can eat biofilm and algae), and fish can all be factors and the result is a smaller shrimp.

tamsin

Discussion Starter · #8 · Jan 13, 2011

I doubt it's the fish as the cherry barbs aren't big enough to threaten them at 1/2" plus. They hang around happy enough at that size.

What do you recommend feeding them? They don't tend to show much interest when I tried cucumber etc. and they don't often come down off the moss to checkout the sinking fish food.

I'll pick up a couple more - I guess if they grow that will indicate if it's a genetic or environment issue.

tamsin

Discussion Starter · #9 · Jan 24, 2011

I've found two dead ones since I posted but nothing obviously out of the ordinary about them.

I'm running out of test kits, phosphate is also fine. Can TDS effect shrimp? The tank is running about 400 which is 2-3 times our other tanks.. could that be the difference?

kharma

· #10 · Jan 25, 2011

Your nitrates our 25-50?

tamsin

Discussion Starter · #11 · Jan 25, 2011

Probably on the lower end. The test kit came out at 12.5 the drip stick about 25.

I'm beginning to think there is a trace of something I can't test for. I added a couple of ember tetras last week thinking the were small enough to not add much load, acclimatised them gradually and lost half already. Swimming about mid tank and feeding in the evening and dead in the morning.

I know shrimps are more sensitive but it's obviously effecting fish too.

Navigarden

· #12 · Jan 25, 2011

Do you run co2 to the tank at all? Or dose Excel? Do a

tamsin

Discussion Starter · #13 · Jan 25, 2011

I think it lost the end of your post?

No co2, no excel, I use tropiflora liquid plant food (no copper I checked) about half of standard dose and root tabs a couple of times a year - again well below standard dose. Nothing else added.

hbosman

· #14 · Jan 25, 2011

How often are your water changes and how much water do you replace?

tamsin

Discussion Starter · #15 · Jan 25, 2011

I did 25% two weeks ago and 5% at the weekend as I had some spare mixed up. I usually change about 25/30% every couple of months as there is virtually nothing in there and I top up any evaporation with straight RO.

tamsin

Discussion Starter · #16 · Jan 28, 2011

I noticed in the last few days I've been losing shrimps and even the amano are looking unhappy. I'm pretty much convinced there is some contaminant in the water.. I took a water sample to my LFS and they couldn't find anything in the standard tests either.

I plan to completely empty the tank and restart it. I set up a small tank with a sponge filter, heater and some plants, and half filled in with water from the tank to minimise stress. Then caught all the shrimps and put them in. The over the last 12hrs I've been gradually topping it up (its now 2/3 full) with water from another tank (with a health fish/shrimp population). However the shrimps are not looking good. About half are currently lying on the bottom waving their legs in the air.

I don't know whether to change out more water which means they have fresh water but have to cope with the change or keep going gradually?

Is there any chance of the ones not looking good recovering?

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Gatekeeper

· #17 · Jan 28, 2011

When was the last time you changed the RO and Carbon Filters? You sure there is no chlorine getting in there?

tamsin

Discussion Starter · #18 · Jan 28, 2011

I get the RO water from my dad, I know he was just planning to change them but I'm not sure if he has or not yet - I'll check when he gets back from work. He uses the same RO water for his freshwater and marine tanks and hasn't had any recent loses.

Thanks for helping

Gatekeeper

· #19 · Jan 28, 2011

I am going to be honest here. I'm not sure you really have a "problem" here or just a combination of bad events that are transpiring.

Where are/do you buy your fish? The fact that the cherry barbs and loaches are hanging on for such an indefinite period of time is the true guage. If there were real problems, these fish would be affected too. Now some will argue that fish adjust to water parameters... I can agree with that. But they will not adjust to a corrupted water column.

If things were really wrong, I think you would see alot more die off from the fish and shrimp.

In my personal opinion, I think maintaining course is the only true test. Continue with large water changes and normal feeding.

As far as the shrimp growth, try getting some higher protein foods that are specifically made for shrimp. This could help with better more healthy growth. I would certainly reccomend adding some new RCS from an alternate source, but this is a supplement to their growth and longevity as a colony, not a solution to improper care (not saying that you are though).

20 gallon tank is more than enough to raise RCS. Thats the size I have used for years with no issues.

Cherry barbs will pick off baby shrimp from my experience. May be why your not seeing so many.

Good luck.

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tamsin

Discussion Starter · #20 · Jan 28, 2011

I can't understand why I don't lose the barbs/loaches either. My fish come from two LFS, both my parents and sister also keep fish and buy from the same place.

If I go back a bit there is a history of die offs, I've never managed to get the tank fully stocked. I like to add things gradually so over the last year I've tried several times to introduce more fish, always a few at a time and 3-4 months apart. So, for example, I added 5 cardinals and I lost 4 plus one of my existing fish, I moved the last one into my parents shoal and it survived. I introduced a couple of platties twice, lost all but one which passed away a couple of weeks ago. Through all this the shrimps are merrily breeding away and water seems fine. Then most recently same with the little ember tetras, after losing two I transfered the rest to my parents tank - so far no more losses.

The last weeks or so it seems to have come to a head and my shrimp population has been decreasing and I've been finding dead ones. I went through my tank and fished out all I could find which was only 9 plus one dead and one on the way out. The others aren't looking particularly happy either. Transferred them to a small tank with the same water so I'm guessing they were already stressed or effected by something and that was enough to finish them off.

I just can't work out what's going on

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