Backyard Aquaponics
A place to discuss aquaponics

Thanks TrickyUK. Glad you enjoyed it. Thanks Fabian. I have some old underfelt over the worms now. I really need to expand my worm farm a lot! Been lazy in that dept. I have now moved the mozzie fish in to the new tank on the big system where they seem happy.

TCLynx. There is indeed. I am really considering going down there soon to investigate the costs of having a mold made up.

Chilli. The lecture course is now set for next year June 7 and 8 and on the 9th peeps who want to can come to the farm and see the big system. Really exciting and I am a bit nervous. Lots of work to do before then.

Had my first real system problem in over a year. I noticed the auto fill in the sump constantly refilling on the pump cycle. Took me quite a while to find the leak as the sand is so well drained here that it does not even show on the surface from 250mm down. eventually found a broken 45 degree pvc junction totally broken off. I guess thin walled waste pipes and fittings are probably not a good idea for burying underground. Should have used the thicker walled high pressure fittings and pipe for more reliable plumbing. It could also have been a slightly faulty fitting though as it busted off really cleanly at the place where the pipe fits in and it goes into the bend part. Looks like there was only a sliver of plastic in that spot.

Glad you found where the problem was.

I finally got the rotomolding company to get back to me and the prices they gave were like more than double what they had indicated when I spoke with them before. Ugh.

Things cruising along nicely although still no backup. Had a power failure but fortunately I had a 12 volt air pump and used the quad bike as a generator.

I have been harvesting masses of chard, brussel sprouts, spring onions and leeks. Tomatoes are well on their way in the greenhouse. I need to get a fan on the greenhouse. I need to buy a fan for it an I am not too sure what to go for. I think I may need some kind of roof mounted fan. My original position for the fan will blow directly on the plants. Any Ideas. I have a temperature controller but probably need some kind of control box. The greenhouse won't really work until I have the fan and thermostst control working as currently just manually opening windows when it gets hot is not really working. Tilapia have not grown as a result. Need to work on it.

The outdoor system is brilliant. The cement dams are brilliant at keeping water cool for the trout. It is warming up nicely here. Outside temps hitting 25 to 30 degrees some days and my water temps are still 15 degrees. A testament to the brick system I think. I am contemplating getting some small trout and trying to get them through the summer. Last year max water temps where about 27 degrees. If I put in more air stones and more shading around the sides of the growbeds and fish tank, basically box it in with 40% shade it could work. If I take the trout out again like I did last year then I have dismal plant performance in summer. I wanted to do carp but can't find a source. The Tilapia I intended on taking from the greenhouse are still tiny and will probably not help much in the big system.

It would be interesting to try and go through summer here as it would prove it to be possible. Temperatures can hit 40 here so it would be quite a challenge. I think the brick tanks act like big ceramic cooling vessels like people use for water coolers in offices. I remember my dad having one in his office when I was a kid. Its pretty cool.

In regards to cooling, have you ever looked into a evap cooler or I think they call them a bakki shower??
not quite sure how your climate is in SA, but if you dry area and do not experience high humidity often, then they could be a quick, cheap and effective solution?

regards

Matt

Matt...Summer conditions here are good for evaporative cooling. Hot and very dry. I did play with the idea last year but not extensively. I am thinking if I can get a few bread crates and fix them together and have a matrix of black pipe running through them and then fill the void spaces with some kind of absorbent material like they use in the coolers and then run water through the pipe matrix and drip it out onto the material at the top of the device. Hang the whole thing over the tank and see if it works. The only thing I don't know is what is the material they use in the coolers? It looks a bit like shredded cotton based paper or something like that. You want something absorbant but it must not rot too easily, and it should allow the air to pass through. There is a pretty consistent summer south easter wind which will really help as I won't need a fan...

My water temps today are around 18 degrees. Outside temps are 30 today.

I have the mosqito fish culture tank up and running now with a improvised shade lid.

Also hooked up another black tub growbed in the greenhouse. I am hoping it will act as a heater for the water to a certain extent.

Temp here hit 40 today and tank temp got up to 31, so I've also been looking into cooling and will probably go with a DIY bakki shower in the next few days like this one:


Looks like it'll cause a lot of water loss and might need a fan blowing through it to to be effective, but should be able to put it together with what's around the house..

If you google "bakkhi shower"... and select images... you'll see squillions of DIY examples...

And you'll find squillions of posts about them on the koi forums...

Yep, kill two birds with one stone... well three really.... nitrification, denitrification/CO2 offgas.... and cooling...

Here's my DIY Bakkhi...

Hay Rupe,
can you get trout through summer with just the bakki shower???
Do you have any figures in regards to the Temp differences and flow + water useage?

regards
Matt

sorry for the hijack brian

My whole system was enclosed with shade cloth... which cut down any air movement significantly... (until a storm got under it and ripped the lot off)...

So it probably would have benefited from more air flow... or fans....

In retrospect... I really needed to double the flow rate as well...

All my research suggests that ... in terms of cooling... the showers actually work better at lower temperatures... rather than in the height of summer...

Nah, I never did really get around to measuring any temperatures.... it was just there... whether or not it lowered the temps is hard to say...

Principally I used it for nitrification/denitrification.... to deal with the nitrates, as the system was RAS rather than AP...

But with the shower, working with weather patterns.. and water changes... I did get my trout through to over 1kg...

It certainly assisted with DO for the trout over summer... but the water temps still meant I basically wasn't feeding.... not sure if it was really worth the effort...

So Rupe... the water just trickles down through the media and gets cooled on the way through? Nothing too fancy?

So now the question is how to make this thing? 'Borrow' some bread crates and cable tie them together and stuff em full of shade cloth off cuts and bits and pieces? Will probably need a separate pump to continuously pump to the shower head?

Alternatively a blue barrel riddled with 25mm holes stuffed with the media....

yep main thing is making sure there is air flow since the cooling happens when water evaporates.

The "bakki shower" is a high flow style of "trickle filter"... rather than the standard low flow/trickle filter.... and benefits from high flow... min 6000L/h....

As I said google... and check the images... or search the koi forums... the koi guys love the bakkhi...

You'll find heaps of examples of "milk/bread crate" systems...

Check this thread... http://www.koiphen.com/forums/showthrea ... er-Filters.

Plenty of airflow around these parts TCL. We have good strong South easterlies here most summer long. I noticed last year the water temps dropped a few degrees when the wind was nice and puffy, and as soon as it stopped the temps rose very fast. That generally does not happen too often. People always moan about the wind in the cape. I guess just the evaporation from the tank surface was what caused the temp drop.

I wonder how much of a difference this bakki shower will make to the temp? Last year my tank went up to 28 so I really only need to lose a few degrees to keep the trout going.

Problem may be.. will I have any trout left? There are lots left but at the rate I am pulling them out I am not sure they will last. They are 1.5 kg now so they could get huge if I can push on through.

I wonder if I can get more fingerlings now? I will need to call the hatchery. Also if I chuck in a whole lot of small fingerlings now the big fish will probably munch the small ones? guess I could move the mozzie fish culture to the greenhouse and put new fingerlings in there.

I had a good look at google Rupe....

Two trout karked it last night. No idea why at this point. I have not seen the dead fish yet, have not been back there... but perhaps there was a power outage in the middle of the night. I really need to get the backup sorted or at least a siren or something to alert to a midnight power outage. I also have not tested water for absolute ages as all my test kits ran out. its really dumb how they sell a test kit that has 3 bottles of chemicals and the test requires 7 drops of each but one bottle is a lot smaller than the others. WTF? It was also sweltering hot yesterday so perhaps the temps had a part to play although I doubt water temps where in the danger zone. It's cool again today.

I have also noticed the saltiness of my water has diminished over time. I have no way of testing, except the taste test, for salt but I only salted to 1ppm so I am just going to salt as if I am salting to 1ppm again. 8kgs of salt in 8000 liters of water?

When I had the serious leak I probably lost most of the salt from my system. I am assuming the pH is still high so I guess fish will be sensitive to ammonia poisoning.

Considering harvesting most of the trout at this point before a major disaster but the problem is no freezer space and then I will have no fish to power the system. The fish are around 1.5kg now so pretty big.

Spent my Sunday evening reading your thread from beginning to end and like a good book it was very hard to stop. I have lean a lot and can't wait to start my system!!