# Butt crisis



## aec34 (22 Jun 2021)

(Sorry, couldn’t resist.)

I use rain water for my shrimp tanks, but with the lack of rain, and then the warm, then the showers, the water has gone cloudy/yellow/slightly smelly. I have two covered barrels coming off the shed roof, daisy chained together, and I draw from the second of them. I think I’ve been quite spoiled in that the water has been crystal clear for the last year.

I’m confident there is no man-made pollution, and this is just what happens when you leave a barrel of unsterilised water in the sun. Is this going to do anything bad to the tanks? My gut says not - but should I do anything differently for a while? I don’t have fish, so any small critters will have to be hoovered up by the shrimp. I only have 20 and 10 l tanks at the mo, so am not changing vast quantities.


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## ScareCrow (22 Jun 2021)

I'm in the same butt........I mean boat. I've not had problems in the past when I kept killies or currently with my 85 or so 4 week old kribensis. However, I have been thinking of getting a small pump/air pump and solar panel to keep it from stagnating. If I go the pump route I'll probably fabri-coble an activated carbon reactor on to it. I try to avoid harvesting the first hour or so of rain after a long dry spell but some activated carbon would help remove some of the pollutants heavy metals in the water I'm unable to avoid.


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## dw1305 (22 Jun 2021)

Hi all,


aec34 said:


> Is this going to do anything bad to the tanks?


<"Probably not">. I have _Daphnia_ in my water butts, they provide <"an indication of pollution">. Basically <"_live Daphnia = OK_">.

cheers Darrel


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## aec34 (22 Jun 2021)

Thanks both, that’s reassuring. Done a change on one tank and shrimp are fine so far - and actually perhaps perkier than normal


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## dcurzon (22 Jun 2021)

Was it only me that went all Beavis and Butthead?


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## jaypeecee (2 Jul 2021)

dw1305 said:


> <"Probably not">. I have _Daphnia_ in my water butts, they provide <"an indication of pollution">. Basically <"_live Daphnia = OK_">.


Hi @dw1305 

I would politely suggest a degree of caution here. I think you'll find that Daphnia are tolerant of some ammonia in their water. Please take a look at the following:



			https://www.ideals.illinois.edu/bitstream/handle/2142/9811/inhscaev01990i001_a_opt.pdf?sequence=2
		


This is an extract from the above document:

"Daphnia magna was less sensitive to ammonia in both acute and sublethal effects tests than were the fish species tested. The lowest concentration of un-ionized ammonia found to cause an adverse effect on the daphnids was 1.3 mg/L, while effects on fish occurred at concentrations as low as 0.05 mg/L".

JPC


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## dw1305 (3 Jul 2021)

Hi all, 


jaypeecee said:


> I would politely suggest a degree of caution here.


I'd agree to some degree, _Daphnia_ would be tolerant of lower oxygen and higher ammonia levels than most fish. I'm sure there could be circumstances where it wouldn't work, but on the balance of probabilities I still think it is a viable method

When you run an aquatic organism bioassay (on treated waste water) <"you use a suite of organisms with different tolerances to a range of pollutants">. That isn't an option for any of us, outside of specialist labs. However:

_Daphnia_ are very sensitive to pesticides. 
Easy to identify.
Found in a lot of peoples water butts, and
I've used it successfully as a method for ~30 years
So I'm going to stick by "_Live Daphnia = OK_".

cheers Darrel


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## mort (3 Jul 2021)

Is this issue likely caused by pollen being washed into the butts? I have covered water butts and have noticed a film on top that looks like it's made of pollen.


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## jaypeecee (3 Jul 2021)

dw1305 said:


> So I'm going to stick by "_Live Daphnia = OK_".


Hi @dw1305

That's fine. Each one of us has to weigh up the pros and cons. I included the information above to draw attention to something that took me by surprise when I first discovered that Daphnia are surprisingly tolerant of ammonia.

JPC


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## dw1305 (4 Jul 2021)

Hi all, 


mort said:


> I have covered water butts and have noticed a film on top that looks like it's made of pollen.


Pollen would have a large BOD value (it is rich in protein), but I can't see it would be a problem, mainly because the amounts are never going to be huge.


jaypeecee said:


> Each one of us has to weigh up the pros and cons. I included the information above to draw attention to something that took me by surprise when I first discovered that Daphnia are surprisingly tolerant of ammonia.


There would definitely be organisms that <"were a lot more sensitive">. One reason why we know that _Daphnia magna/pulex _ are relatively tolerant to ammonia is that there is a <"large body of scientific work"> using it them bioassay organisms.

I'm not claiming that methods like the <"Duckweed Index"> or <"Daphnia Bioassay"> are perfect, or fool proof, but they both <"combine accessibility"> with <"ease of use">. 

Their great advantage, for me, is that you don't need <"test kits"> or <"meters">, all you <"need to do is look">. 

cheers Darrel


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