Backyard Aquaponics
A place to discuss aquaponics

This morning's readings:

O2 approx 10-12
pH 7.7
Ammonia - 0-0.25
Temp 20c

All looking good I think

andrew my air pump was running warm and I was worried about it so ..

small computer fan, wired it to a 9V mobile phone charger and it runs constantly cooling the pump housing,
works great

systems looking good, good luck with the trout !

Thanks Boris,

I've been considering some solar-panel-powered fans for the tunnel - have heard that computer fans are the way to go!

Andrew

Can you please keep us all up to date with your water temperatures in the polytunnel. We are interested as we have cobbled together two old polytunnels into one 14 feet wide by 80 feet long and may try putting a fish tank inside buried in the ground like you have done. The inside temps may be much too high for trout but your readings may give us a clue as to whether we give it a go.

WD and OH.

Our trout tank is above the ground - the sumps are buried. Temp sitting at 19-21c, but I am leaving the doors open at the moment! My thoughts are that the trout would be better outside the tunnel in an insulated shed. Maybe.

I'll keep you up to date!

Fish were a delight today, easy to see, splashing and having fun, loving their food.

Readings this AM

Temp - 20c
Ammonia <0.25
O2 - 12+
Nitrate - 0

Andrew

My fault I thought the buried tanks were your FT's. However still interested in the temps in the covered tanks.

I think you are right about sticking the tanks outside,especially with trout being so sensitive once the temps go over 20-23C. Highest we have had in the tanks is 23.7C and they were OK but if the tanks were in the polytunnels where we have registered 142F (don't ask me to convert that), the fish would be dead and cooked.

WD and OH

142F = 61C. Poached trout.

We've had the polytunnel reach well over 40c with the doors closed earlier in the year and the water has only got to a max of 23. It seems pretty stable.

Yesterday we lost our first fish – she got caught up in the net that is over the top of the tank to stop then jumping out!

Feeling a bit sad that we’ve lost one already, but it did give us a chance to weigh and measure one accuately. We’d been working on a weight of about 10g and thought they were about 4″ long. The one who came out is 18g and 4.5″! So now we understand why they were a bit hungrier than expected – we’ve upped their feed from 30g/day to 45g/day (about 1% of body weight). Here’s the pic of the little one who sacrificed herself so that the rest could get properly fed:

Trout are growing well - checked them yesterday and they were up over 30g - almost doubled in the last 2 weeks.

Water temp seems to be stable at about 20c.

What are your ambient air temperatures like there Andrew?

I did wonder why some of the others over in the UK are trying to grow Tilapia when it seems like trout might be a good call in many areas year round.

The tanks are inside a polytunnel which fluctuates from about 15c up to 35c. Interestingly I hgave been wondering about whether a short season of tilapia might be best in the polytunnel as I'm currently having to have the polytunnel cooler than is ideal for the plants to ensure the Trout don't get too toasty. I have a feeling we could easily keep the water temp above 20-25 for 4-5 months with no extra heating.

Good morning Andrew

We toyed with similar thoughts to you on switching from trout to tilapia for the hot weather and swiftly kicked the idea into touch, and it has seemed to work out for the better as we have a small business selling trout which pays for the feed and some of the electricity but when we ask the customers about tilapia the reply seems to be "WHAT"
At the end of the day, commercially, the fish and plants have to pay for themselves and Tilapia in this step of the woods are a No No.

You could try sticking a tank outside for your trout and connect it into the AP system,including the inside tanks containing tilapia.

We can have a natter when we see you next week.

WD and OH.

Good points WD & OH - well have a chat about it on Tuesday.