Backyard Aquaponics
A place to discuss aquaponics

TC, I would think Blue Gill would do well in Florida - actually a favorite of mine! Have you tried them?

Mark

Has anyone tried water striation to regulate water temperature naturally? Also moving water absorbs less heat so constant flow would reduce heat gain as well.

Water Temperature Striation
Top Layer- epilimnion- 73.4 F to depth of 23 feet
Middle Layer- metalimnion- 73.4 F to 41F from 23 feet to 44.3 feet
Bottom Layer- hypolimnion- 41F from 44.3 feet on

Angie, I live in Texas, here's the pick and shovel, have at it! A chelate layer sits at 0-15ft depending on where you live here. Besides That would be one heck of a FT to have the right proportions.

All tongue in cheek

But I will attest that stratification occurs readily here. Most of the lakes stay turbid most of the year. So about 10ft down there is easily a 10-15F difference. So if one is suitably situated to a deep enough lake you could rig up a exchanger to lower temps in the FT.

Water stratification can result in major fish losses in certain circumstances where the layers "invert"...

The lower layers are almost always oxygen depleted... if they invert... the entire fish stock is usually lost within 30 mins due to oxygen starvation...

Personally, I think Atlantic Salmon tastes terrible when compared to Sockeye.

Also, there have been reports in the US over the last few years that the farm raised Atlantics have an omega-3:omega-6 ratio that is much lower than their wild counterparts. I don't know if that's supposed to be related to the feed or the conditions though.

Are you serious..! I love Atlantic.


Yep you'd be right. ALA, DHA and EPA are the 3 types of Omega-3. DHA and EPA (good for the noggin i.e. brain function) are rich in wild salmon. In farmed salmon ALA is typically the dominant acid/oil. But our body can convert ALA to DHA and EPA, but just not very well. However, farmed salmon are still better for Omega 3 in the diet than no salmon.. But farmed salmon contain higher concentrations of omega 6 fats than wild salmon too. But that goes for many other species also. Especially cat fish I believe which can contain up to 5 times the Omega 6 fat content of their wild counterparts.

But I'm curious how my atlantic salmon will taste none the less. I'll let you know in about 9 months.. 6 days since insertion and not one fingerling has died yet.. But the water temp is hovering at a steady 20 degrees on top and 18 degrees at the bottom so its 'careful as she goes'. But that's about as hot as it will get here..

WTF is Omega 6? and what's it do for the body?

Personally I cant taste any difference between Trout and Atlantic Salmon when its been grown in freshwater.



You hope. If my memory serves me correct you had a 36 degree day last month and its not impossible that you could get another before the summer is out. With your growbeds being in that greenhouse your water would heat up pretty quickly so I would be keeping some ice on standby just in case. Those Tassie fish cant handle the warmer water temps as well as the mainland fish.

Hey Kuda.
Like everything in life there are good and bad fats. All need to be consumed in moderation. Both Omega 3 and Omega 6 are good unsaturated fats found naturally in 'oily' fish. Omega 6 is an arachadonic acid and is converted eicosanoids which then bind to a huge array of receptors in nearly every cell in the human body.

However, when there is an excess of Omega 6 over Omega 3, then things can go awry Just like saturated fats, excessive Omega 6 is associated with heart attacks, heart arrhythmia's, strokes, bone and joint problems such as arthritis and osteoporosis, obesity, and some cancers (apparently). It can even make you a moody bugger.

Mediterranean diets include whole grains, fresh fruits and vegetables, fish, olive oil, garlic, as well as moderate wine consumption woo hoo which is rich in Omega 3 and low in Omega 6. Hence, much less heart disease. But western diets with a lot of meat are rich in Omega 6. There needs to be a good balance of both 3 and 6 fats of about 1:4 because they both use the same enzyme for conversion to other things in the body which is why too much 6 reduces the usable amount of 3.

But in farmed fish this ratio can change depending on the feed and breed of fish. i.e. the catfish can be a real fatty in the wrong direction (up to 5 times) when farmed. That's why its good to know the fat content of the feed you are using, and also the natural tendencies of the breed of fish being fed. Over feeding atlantic salmon can give rise to a significant elevated level of fats c/w their wild counterparts. I 'think' salmon are not fed for a few days before harvesting to reduce this amount of fat in the outer layers.? (I'll check on that)

It gets quite scientific really but its great fun to try and work all this out. It makes aquaponics really cutting edge when it comes to outcomes of raising fish in sealed environments. But as mentioned, know your feed implicitly, and then what it does to the fish you are giving it to, and what temps change the diet needs of your fish.
Hope that helps.
T

Absolutely its not impossible.... And you are spot on with the glasshouse..! I have just sank my thermometer to the bottom of the tank to check out the tank temp. Its 17 here today, 23 in the glasshouse, 18 top water temp, and bottom temp.
I am putting up a shade sail this weekend to cover the tank just in case we have a hot day, and I have 4 air-stones running at about 50lpm.
I lost a fish yesterday though. 1 out of 80 in a week is ok I guess. I think it just carked it from the transfer.. Not totally unexpected. All others are lazily swimming around and seem happy enough.

Be really careful in borderline temps... 1 or two fish may be weaker than the others, and secretly die.
This can kill your entire tank within an hour of you noticing that they're unwell.
make sure you have good vis, and check your tank for sinkers as well as floaters.

Yesterday, is hanging over the inside of the tank with a pair of goggles and a snorkel to see if there were any other 'sinkers' ok..?!

My wife came out and just stared at me with this really weird kind of grin.. All I heard as she then walked away was 'oh my god'.

Perhaps you could share a photo of the look on her face... as you pass her the goggles and say "your turn...." ....

I'm picking it would be a definite... hand on hip moment...

I want to see a SCUBA Steve moment with Tony as the star!