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Osmotic balance in shrimp?

Big G

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20 Apr 2020
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Happy boxing day all.

Just trying to pin down some issues with a new batch of cherry types I've got.

It's clear that they struggle with the co2 injection level that was present when introduced as signs of distress, even after a long slow acclimation, that emerged with 24 hrs, were relieved by a fairly large water change and taking the co2 offline.

I think I'll keep co2 out of the equation , tweak my lights and ferts regime to try and offset that loss of additional carbon source until I can work out what's the issue.

I've run ammonia( API & Seachem) nitrites (API) and nitrates (API, Salifert and JBL). Also got a Seachem Ammonia alarm litmus-type 24 monitor in the tank.No test-detectable in the first two parameters and Nitrates around tap @ 35-40ppm.

Filter media clean etc.

I've read that adding co2 can tip the balance of osmotic gas exchange in the shrimp to not allow expulsion of co2 so they build up toxicity and show signs of anoxia. I understand that co2 saturation and oxygen saturation are not competitive and can co-exist.

If that's the case could I test for DO in a sample of tank water, attempt to raise it with say, an airstone on a pump and then seek to reintroduce an initially very, very low initial co2 injection for a very low initial amount with the aim of raising the safe threshold at which normal shrimp respiration crosses over into hypoxia/anoxia?

I'm not wedded to co2 in this tank and, because of losses, it's not something I'll dash back into until I'm satisfied I'm getting a raise in o2 from air injection tests.

More sort of mid-term curiosity and a desire to see if I can aquire a balanced planted tank where shrimp can exist with a modicum of co2 for plant advantage.

I daresay its going to be dependent upon the individual shrimp, how they were raised and their genetic capabilities.

I can quite easily deploy the co2 rig elsewhere on a plant-only display tank.

Im no sadist and really treasure my critters. Just wondering if I've understood the science correctly.

All the best

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Hi all,
I've read that adding co2 can tip the balance of osmotic gas exchange in the shrimp to not allow expulsion of co2 so they build up toxicity and show signs of anoxia. I understand that co2 saturation and oxygen saturation are not competitive and can co-exist.
Shrimps have <"haemocyanin"> as their oxygen transporter, which less efficient at oxygen transport than haemoglobin and they don't have as efficient a blood flow system as vertebrate animals with the heart pumping blood around the haemocoel and, relatively undifferentiated, vascular system.

If you have high CO2 levels in the water it lessens the CO2 exchange gradient between gill and water and the shrimp has to breathe (beat its gills) more quickly. If that doesn't have the desired effect then CO2 levels will build up in the body, with potentially fatal results.
I'm not wedded to co2 in this tank and, because of losses,
I'm going to tell you to turn the CO2 off.
If that's the case could I test for DO in a sample of tank water, attempt to raise it with say, an airstone on a pump and then seek to reintroduce an initially very, very low initial co2 injection for a very low initial amount with the aim of raising the safe threshold at which normal shrimp respiration crosses over into hypoxia/anoxia?
You can't easily test for DO, <"without a DO meter">, but you can maximise oxygen. Have a look at <"Aeration and Dissolved Oxygen......">.

cheers Darrel
 
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Hi all,

Shrimps have <"haemocyanin"> as their oxygen transporter, which less efficient at oxygen transport than haemoglobin and they don't have as efficient a blood flow system as vertebrate animals with the heart pumping blood around the haemocoel and relatively undifferentiated vascular system.

If you have high CO2 levels in the water it lessens the CO2 exchange gradient between gill and water and the shrimp has to breathe (beat its gills) more quickly. If that doesn't have the desired effect then CO2 levels will build up in the body, with potentially fatal results.

I'm going to tell you to turn the CO2 off.
Thanks Darrel.
Co2 went off 36hrs ago. 👍

Do you think the exchange gradient effect is amplified by small volume of water i.e. the ramp time to onset of anoxia is a sharper gradient as any given bubble rate has a more immediate and dramatic impact?

Would make sense that, along with the difficulty of maintaining other stable parameters, a smaller body of water has less room for error with co2 injection.

If the above is true I think that's it for co2 in combination with shrimp and ornamental nano tanks.

Will rig on a plant-only, large tank (maybe with Kribensis - always loved their sophisticated behaviour ) in the future. Will shut down and mothball the co2 rig for now.

I consider snails to be an interesting and indispensible addition to a planted tank and wouldn't be without them but again, co2 and commensurate ph drop is a factor.

My water is hard , ph 7.8 out of the tap and highly buffered. I never got more than a 0.5 ph drop in my profile at most. They never gave me any indication of distress and they're fine, thank goodness. I think that might have blind-sided me a bit in my inexperience.

Goodness- how I with I had got further with my hard sciences at school.

Appreciate it D 🤜

Peace

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Hi all,
Would make sense that, along with the difficulty of maintaining other stable parameters, a smaller body of water has less room for error with co2 injection.
Definitely, I've never been a CO2 user, but it is exactly the same as the other parameters, the smaller the volume of water the quicker things happen.

I think shrimps and snails are complementary and that a tank with snails is likely to have healthier shrimps.

cheers Darrel
 
I’m running a oxidator in one of my first tank as I was curious about how it might help plant growth and affect the green hair algae the tank is living with. My thinking was that even though we know plants are a net exporter of oxygen over a day/night cycle, the addition of critters and DOC as pure consumers of DO, would mitigate it’s availability, especially during the night cycle. If plants (and critters) are using oxygen in the night cycle as part of their metabolic processes, raising available DO might benefit both (over and above good surface agitation)

I get the impression bubblers, air curtains and such have been dumped in the loft along with sunken galleons and orange gravel by many and fair enough, it’s not so natural and I’m not needing that disneyfication as I’m not 8 ( I’m ten and very proud of it :(). Is there a danger we throw the baby out with the bathwater on, particularly, non-photoperiod air pumps, reactors and diffusion?
All of my memories of diaphragm air pumps are bad from The Old Days of course; noisy, rattly, unreliable chunks of bakerlite or pressed steel, crabbing their way across any surface they were put on and pushing out less air than was worth the effort.

The oxidator is interesting and provided I can secure a reasonably priced supply h202 i’ll stick with it and see if I can discern any long term benefits.

I’ve got a new Eheim 100 coming and a limewood bubbler coming and might give them a shot too in another tank.

All the best

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Eheim 100 coming and a limewood bubbler

This is exactly what I run on my EA 900 from 00.00 to 06.00. Not totally silent but very close. Impressed with the lime wood diffuser it produces bubbles which are the smallest of all diffusers I have tested
 


If you can get past the jocularity (very marmite) and park some of the hard figures this guy quotes (which seem a little too ambitious bordering on reckless to me) there’s something valuable in here to me. Setting those caveats aside, is he basically right? That the issue is not so much gassing of co2 but an unfavourable balance of partial pressures (that unfavourable balance being much lower for inverts, by and large, than for fish).

all the best

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This is exactly what I run on my EA 900 from 00.00 to 06.00. Not totally silent but very close. Impressed with the lime wood diffuser it produces bubbles which are the smallest of all diffusers I have tested
Mine turned up and well, it’s still too loud for a bedroom imho. Classic solid Eheim construction. I’ve found a couple of intriguing methods of quieting the hum and will pursue those with the ‘cable suspension in glass jar ‘being the least technically demanding. There are replacement diaphrams available from Eheim so I’m confident that having a little look inside should be fine if I’m careful and go that path too.

The limewood is good but not really good enough at creating sufficient lingering time for the o2 to be diffused directly. Perfectly good for surface turnover.

This is helpful, at least I found it so;

An article by no less than our very own dw1305 ( I hope you don’t mind me re-posting it here Darrel as you had already linked to it in another UKAPS thread. I will of course remove it if you would prefer. Bg)


I’m having no luck finding any EPDM diffusers that aren’t industrial in scale and price or need much higher wattage pumps.

Might look into the hydroponic/aeroponics world and see what they’ve got.

All the best

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Hi all,

I mention it as often as I can. I wrote it a long time ago, and it has had a few homes, but I'm still proud of it.

cheers Darrel
It's excellent Darrel. If all topics within this hobby were so well explained it would be so clear.

Many thanks

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Hi all,
It's excellent Darrel.
Thank you. I got to know a couple of <"Bristol L number keepers"> and began to appreciate what an inadequate fish-keeper I was, but I also found out that <"real experts"> had had unexplained fish deaths, often of large rheophilic plecs, fish, that in some cases, they had kept for a number of years without problem. A lot of this had coincided with the aftermath of the 2010 freeze, and why correlation isn't necessarily causation, I was pretty sure it was in this case and that what had killed their fish was <"emergency chloramine"> dosing, leading to a larger Biochemical Oxygen Demand (BOD), and tipping dissolved oxygen levels over the edge.

I'd already started posting the "cycling" posts, and it would be fair to say that they hadn't been <"universally well received">, so I wanted to write a properly referenced article on aeration. I realised that most web addresses were transient (even for Scientific Journals), which was why I used PlanetCatfish and Wikipedia as the links where possible, so that the article would still "work" after I'd lost the ability to edit it.

cheers Darrel
 
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