Backyard Aquaponics
A place to discuss aquaponics

Does it get cool at night? My trout died not so much because it was hot during the day but that it never cooled down again at night (was 85F/29C air temp the night they all died, 71F/21C water temp FWIW)

The air temp at night will be lowering to about 14-16 degrees, we will make all the cloth and surrounding pavement soaking wet before sleepy time. So it should cool the FT temp with a few degrees during the night. We'll also top-up with cooler tap water.

The trout have survived the previous night with a water temp a little over 21 degrees. I understood this was not favourable but acceptable for the fish. According to "the Amended Preliminary Draft Environmental Assessment (APDEA) 5.2.4 Aquatic Resources" I found on the web;

Stressful and Lethal Temperatures
Based on available literature drawn largely from laboratory studies (Cherry et al. 1977,
Raleigh et al. 1984, Currie et al. 1998, Coutant 1977) the upper incipient lethal
temperature (UILT) for rainbow trout is within the range 25 to 30°C. Eaton et al. (1995)
identified upper temperature criteria for rainbow trout as 24.0°C. Myrick and Cech
(2001) report critical thermal maximum (CTM) tolerances of 27.7 to 29.7°C for juvenile
California steelhead, and as high as 32°C for Eagle Lake rainbow trout acclimated to
Attachment I
Copyright 2007 by Southern California Edison Attachment I February 2007
25°C. The temperatures that may be considered too warm or deleterious for a fish
species depend upon the duration of exposure. USEPA (1976) identified maximum
weekly temperatures for survival for rainbow trout as 24°C. UILTs reported by USEPA
(2001b) for rainbow trout range from 24 to 26.9°C.
For the purposes of the analysis in the PDEA, a daily maximum temperature of 24°C
was selected as a temperature evaluation criterion for short-term high temperature
exposure. The use of 24°C for short-term exposure may be considered conservative
(overly protective) based on available information. The exposure considered in the
evaluation criteria for daily maximum temperatures is generally one-hour or less. Since
the temperatures cited above represent 24-hour to seven-day exposures, 24°C the
lowest UILT identified, when used in comparison to an exposure of one hour or less, is
very conservative.

We are paying a lot of attention to the fish at the moment and do everything to cool the system. Should they however give any signs of heat stress, it's BBQ.

Very interesting info, Hoeve. Thanks for posting it.

Here is the link to the complete attachment;

http://asset.sce.com/Documents/Environment%20-%20Power%20Generation/APDEA_AttachmentITroutTemperatureRequirements.pdf

There used to be an edit button but I do not see it anymore. If I am in violation in my previous message because of the copyright (although I mention the source), the moderators should feel free to jump in and remove the part.

Tank temp started out with 21.5 degrees. I took out the first three trout, the bigger specimens, cleaned and ready for cooking;



And some veggies on the side;



Still cooling the system, today and tomorrow still warm weather. After that a period of previous drab summer weather is predicted. So if we make it, and I think we will, we'll have some more growing time for the fishies.

Today is a big day for us, we'll get to eat our first home grown trout!

Fantastic

Very nice Hoeve, I love seeing fish harvests. Another story of success and satisfaction for you I'm sure.

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We've past the hot spell brilliantly, all troutsies are very active and hungry . Water temp is hovering around 20 degrees, and all is well.

During the tying up of one squash plant it came loose out of the good-workable-but ever-so-light-and-mass-less hydroton . It left most of the small roots in the media. Bit of a bummer really, it was just exploding with growth after the warm weather and started to fruit. It's put back with the bed on CF, hoping it will pull through.

Plant went from very uppety into draggy style as seen below in half an hour.



On the bright side we harvested a squash from another plant which grew into this;



Funky and juicy it was.

We've done a check at the local council and got a green light on greenhouse construction. Most materials are in possession already, the salvaged items of a greenhouse-collapse in heavy winds. Attaching it the the existing construction is a bit challenging, it's not plug and play compatible.

And every-time a look at the GB's I imagine a rocket mass heater somewhere . I wonder what will happen.

Rob (Web4Deb) has a rocket mass heater in his geodesic greenhouse as seen here

I'm working on one but it'll be awhile before it gets finished - as seen in my Future System. Mostly still in design stage, although I have pieced one together just to get the layout of the bricks and the vent pipe.

Don't know anyone else on this forum that has a RMH. Have you taken a look at the book "Rocket Mass Heaters" by Ianto Evans? He has it out in hard copy or as an e-book. Really great read, diagrams, dimensions, etc...

I'd love to see what you come up with. You are only limited by your imagination. Hope you can incorporate one into your greenhouse addition before the snow flies again.

Worth ago if you can do it on the cheap. Would you be able to use it to heat water to pump round your system / greenhouse.

OK you guys, smack my and call me Sally, I have started to source materials for the heater. I got me a fine drum with the top lid sawn out and cleaned. All for an ideal price.



Don't mind all the slapped on covers and cloths, we have a spell of warm weather again.

The drum is(very) roughly in the position where I picture it. Wood feed right next to the terrace, thermal mass with flue pipe under the beds and back out next to the drum. The drum will be, , half in and half out of the GH. The GH which isn't there yet.

And we are still growing stuff which is actually food!

Temp is reaching critical heights as we are seeing 30+ degrees today. The glass above the GB's is completely covered in cloths and blankets to block the sun. The FT temp started 23 degrees this morning, a partial water chance brought it down back to 21 degrees. All the ice our little freezer can muster is going in the sump.

An second air pump is huffing away to get the DO level up. The trout are fine at the moment, a small dose of pellets shows vital and swift reaction as always. Feeding is at a minimum.

I expect the max temp with all our care will be around 24 degrees at sunset. Tomorrow will be much less troublesome as the air temps will drop the coming days. I'd like to see the trout I have trough summer. I am definitively looking for a different summer fish next year, but choices are a bit limited here.

We've just learned that this weekend was the hottest weekend in Holland since 1994.

All fishies are fine, so we should be good for the next couple of years.

Congratulations on getting your fish through the heat, Hoeve Innedi. What size are you aiming at for your trout, now that you can keep them growing for longer?

Now that we seem to be able to manage the heat, we will prepare for winter. New fingerlings at our "regular" address will be available in the spring next year. So if all goes well, the trout should be with us for some time. Spring next year they will be about one year old. No aiming size for us, most of them look pretty tasty and agreeable size already .