Backyard Aquaponics
A place to discuss aquaponics

Hi HD, AP fresh tilapia has no off flavors at all. We eat frozen tilapia from time to time and some of it has fishy or off parts. I had trout at a restaurant the other day that also tasted less than perfectly fresh. Expect that AP fish will not have any of these problems as you could be eating it within hours if not minutes of catching it. My wife hates any fishy flavors and she is quite happy with the AP catches so far.

DD, thanks for the input. I'm probably like your wife when it comes to fish. I do like fish but as soon as it has too much "flavor", I'm done. I'd like to figure out how to put this together. One task for the afternoon is calling the state and seeing what kind of roadblocks I run into there. We're configuring things so we can hopefully keep the tilapia happy without too much electricity. On the other hand, having read how quickly folks can eat tilapia compared to yellow perch, makes it worth the extra electricity...

GF, we're going to study the solar collector info and see what we can create. I'll keep you posted on what we come up with and, more importantly, the results.

I don't know if this is of any benefit to you, but I've been reading up on solar collectors and water heating. There's a guy in rural Maine (maybe I found the link somewhere not his site? I dunno anymore), but he heats his entire workshop with solar water collectors and a radiator grid in the floor.

http://www.arttec.net/Solar/BarnHeat.html
or the pdf at
http://www.arttec.net/Solar/SolarHeating.pdf

Maybe it will help with ideas...maybe it won't.

All I know for certain is I'm bored at work

That can not be good bochener...
Not a good sign is that because work is slow/non exsistant?

I was told yesterday that in holland a comany is going around renting roof space off home owners giving them power and installing full solar arrays on their roofs to pump back into the grid...
See what you can find it might be a side line if work is cheesing you off!

good point on the work thing...

As for the solar piece, that is generally what we are looking for. There are some good links in the solar heating water thread here that show how to actually build a solar collector. We'll be working on that once the beds are in and all. My most wonderful husband is out working in the greenhouse while I sit here and "work" at the computer. Speaking of which... back to it.

Tom here. Thanks to everyone so far for the advice. My back loves this old easy chair after digging that hole! Our little red doxie was even helping. She's worn out too.

Tomorrow I'll finish leveling and hopefully have time to get the tank in the ground. That might be ambitious as I still haven't thoroughly cleaned the tank or cut the hole in the top yet. Then the door has to come out of the greenhouse to get the beast inside. We'll put down some old weed block and some of the excess lava rock for under the pallet to help displace any water that may seep in. The tank will be set in 1 1/2" thick styrofoam insulation and some extra metal roofing for support. I think I'll put a verticle pipe in a corner so we can monitor excess water. Does that all sound good?

AFter the greenhouse is back together we'll make a test bed to get the bell siphon to work. Really neat stuff you all have done. We are still going back and forth on the pump size. From what I am reading, if we go with a 25 mm stand pipe, and a 50mm outer pipe our 950 GPH pump should work. On the flip side, if we use the larger 3900 GPH pump, I would assume that we would use a larger standpipe, or is there really no benefit to a larger pipe? It could be neat to create more aeration, but I'm afraid it might be too much and we would have constant cycles rather than 4 or so per hour that we were shooting for. Would there be a big noise difference between either installation? Thanks for the thoughts so far. I am thinking that the differances in the pumps would create 2 totally differant animals. Maybe I'm wrong. Any added thoughts would be appreciated.

This is a real neat forum to visit. Thanks again for sharing.

The shape of the fish can change depending on the current, roundish for slow calm current; long, thin and tuff if swimming all the time. Plus if the current is too fast they won't grow as fast since they'll be spending all there nergy on swimming.
In the organic certification paper they say that fish must have a small current but musn't be swimming all the time. I suppose this would be more adapted to your mentality.
Fish are best eaten after 24 hours in fridge at temp between 0-4°C, it makes the flesh softer and purges some of the taste of it.
The decomposition process starts slowly and starts by the layers of stocked grease in between the flesh, the flesh will then hold together better at the cooking.
The best is to kill it nicely with a good head shock (it is the most respectfull manner to kill a fish since it breaks its brain in one go and stops it from suffering) then gut it and/or fillet it and let it wait in the fridge. If you want to give it a better taste put it in the fridge with some salt on the flesh, then rince it before cooking.
Have fun and nice meals

Hi Tom

I use 3/4" and 1 1/2" pipes for the bell siphons on the barrel half growbeds I am using. Purely a cost saving measure only. I then use a 4" slitted black plastic sewer drainage pipe to hold the media back. When you remove the outer bell pipe there is enough room to get a hand in between the 4" stuff and the 3/4" pipe in order to clean any stray roots out. I did put in extra slits in the black pipe to assist the draining water in the growbed to keep up with the siphon. It does a reasonable job of draining quickly. If you are using a larger volume growbed or if you wish it to drain faster you might want to go with larger pipe diameter.

As for the pumps. Any idea what the flow is on the 950 gph at the head you want/need to pump to?

Very cool and timely info Amacafish! Some of your past posts have made a light bulb turn on for me in the past. Cool indeed.

DRD- liked the tip on the 4" .Again, something I wouldn't have thought of. I see what you're saying about the head. Really, that has to be determined yet. I assume that the head is really the full rise out of the pump. So say that the pump rests a 3 feet below the top of the tank, it still counts as a full 3 feet of head, even tho the output is still in the sump? Vic informs me that there will be duckweed beds overhead, and it appears that she has added some 1/2 barrels to put fruit trees in. If the duckweed beds go to 7 foot high as she wanted, plus say 3 feet down to the pump = 10 feet at which the pump out put would be only 400GPH. It may figure a bit less as the overhead duckweed beds will fill from the bottom of the bed? But then there is the water pressure it is working against to pump water into the duckweed bed. My brain works A LOT on trial and error as you can see! On the other hand, the larger pump @ 10 feet is rated @ 3400 GPH. I'm not experienced on this type of pump so when a pump with a 3/4" outlet says "1 1/2 " diameter is the minimum hose size that should be used for maximum flow" I feel that there must be such a negligable pressure created by these style pumps. I would assume that using a an 1 1/4" pipe doesn't really improve head performance as they aren't meant to be a pressure style pump.

With this greenhouse, it should be quite easy to make a manifold to be part of a solar collector. I'm guessing that a maze of pipe @ the 8 foot level would cut down on the flow from the big pump. Just another thought. Best go back to digging as I seem to be good at that!

Thank you, and if I can help it is even better. I learn about plants and talk about fish, I've been playing with them for the last 12 years, half of my life actually. The best is to find people who are interested in what i'm fond of, actually that is you then thank you too (two?!)

Anyhow when you calculate a head for a volume, you take in count only the up height that is from the top of the water volume, if the pump outlet has not been reduced (never ever do that anyway!) there shouldn't be to much of lost force by friction for the pipes in the water.

If you are planning a water system,

1-think of the total up height from the top of the water you are pumping from (why: water will get into the pipe up to the water level outside the pipe),

2-think of reducing at the most the 90 °elbows, try to work on 45° angles preferably (less friction forces and less turbulence, that's why EB's systems have cut angles so that the pipes or not in 90° elbows)

3-don't forget to have the shortest pipe lenght possible, loops increase the friction and dead zones that can be problematic on long term use (pathogens and anoxic bacteria)

4-Anticipate if you can to T your system somewhere with a short pipe closed with a ball valve, gets usefull in case of purging water out of the system or cleaning. If you go with a powerfull pump, T at the water level and put a ball valve system, this can do close loop in case of trouble or can be used to do a venturi system to inject air in the water

5-Try to go with a little over dimensionned pump because of biofilm in the pipes and maybe making the system evolutive

6-Take the biggest pipe diameter adapted to the pump, the speed will be slower but will be more efficient still because of less friction compared to the volume of water flowing through

Hope this helps and if you really want to get to calculations I might be able to find the basics somewhere in my books.

Yes, helps greatly. It's enlightening for me to see it right in front of me, all in one place. This is certainly a differant animal for me.

So far this am - the hole for the tank is leveled , weed blocked and lava rocked. I just cut this funky hole in top of the IBC that looks like some cartoon hole in the ice (don't tell Victoria) and started cleaning when this black cloud comes over head. Time for a diversion and lunch!

I've been contemplating something similar and thinking of using the earth as thermal mass. If one used insulation around the tank walls and had no insulation underneath it would help stabilize the temperatures. This only really helpful if there is a good chance of overheating....say, if your solar heater may dump a whole lot of heat in over a few days... It will also help moderate night/day temperature swings.

Earth does work as a thermal mass to moderate temps but will also draw heat out of the tank if the tank is warmer than the earth. In summer that may be fine, but in winter I don't want to lose heat into the earth which is why we are insulating the sides with foamboard and the bottom with lava rock. Being in a hole should help to moderate temps overall, I would think. We will also have the ability when we are done to cover the tank with insulation in colder weather to help retain heat.

As for the solar heater, one of the challenges will be to create a way to only run it when the temp in the tank falls below a certain temp. And, ideally would have a way to turn it off if the water coming out of the solar collector was cooler than what was going in. Might never happen, but around here on a rainy day, not sure what will happen. All bridges to cross once the system is up and running.

Aquarium equipement is set for that, you can buy an external thermostat for aquarium heaters. They use them for reptiles too. You could plug one to the pump of the solar heating. It will start the pump when the water temp goes too low. And for the low temp water coming from the solar heating, you could possibly find an inverse one that they use for indoor gardening ventilation, it stops the ventilation when the temp is low and starts when hot. After finding a way to plug one on the other would be easy I suppose. I'd say to plug the pump on the ventilation system which is plugged on the thermostat plugged on the mains.
Give it a thought, just an idea but I know these products exists.

R-value of concrete is about 1 per foot. Dry soil is much higher, other soils are in between. One concept is to make the heat travel at least a few feet to get to air giving you essentially R-3 (probably more like R-6) with a lot of thermal mass (a yard of damp soil is about the same as a yard of water).

In theory it works.......but don't hold me to it!
I'm going to try something similar when things dry out enough here for digging. We shall see.