Backyard Aquaponics
A place to discuss aquaponics

Just starting this one and could use some pointers. Details so far posted here:

viewtopic.php?f=45&t=10949

Question: Why don't more people build in-ground systems. It seems they are waaay more stable and inexpensive to build. Am I missing something obvious?

Thanks All,

Lawrence

Any input helpful.

Thanks!

Such a newbie. This design will never work without pumps everywhere. Yikes! How to handle this???

Seems like a slightly large, complicated system for a self confessed "Newbie"

Also, that stocking density seems rather high to me....maybe with the extra solids removal and biofilter it could possibly handle it, not sure on this one....

Im a bit of a believer in not using solids removal or bio filter in a gravel grow bed system, but I have never done anything as large of heavily stocked as what your proposing....

If you had the FT above ground that would give you reasonably significant head pressure for gravity feeding your SR, BF and GB's....then have a pump in the sump to return it to FT. By having every element of the system in ground, you would need many pumps...

Whats the Thermal Solar for???

Thanks so much for your comments and questions!



On the fast track apparently... Got orders from my lady that it has to be "beautiful and natural looking", especially as it looks right out the kitchen window! In-ground is all there is space and budget for, and hoping this design will transfer well to others in a similar situation where an in-ground FT is all that will will work space-wise, aesthetically, financially, etc...

Thinking also that the larger, in-ground system will be in some ways more forgiving... All these above-ground systems seem incredibly complex too and look like they all need a fair amount of continuous paying attention to?

One thing everyone seems to point to is pump failure. How often does this actually happen (every few years or so?) and is there no way of easily rigging an alarm on it?



Lower density is a better way to start anyway... What kind of harvesting rate could one expect from say, 250 to 500 tilapia under reasonable growing conditions after 9 months to a year's time? How many fish a week or a month is a reasonable expectation?



Simple is good. I was thinking the added SR and BF stages would actually simplify the system in the long run. If the gravel bed becomes the SR and BF how often do they need to be maintenance and or disturbed? When I kept fish tanks, I was needing to clean the gravel every few weeks and it was fairly stinky and disruptive to the plant life growing there...

Thermal solar is being planned to heat the water for tilapia if that's what we end up choosing. Once the system is circulating this winter, I can watch the FT temperature and see if it will need warming up. I suspect will be the case and could always select a cooler temperature fish, but then it's easier to warm the water in winter than to cool it down in summer probably.

My FT is in the ground, timber frame in a hole against the garage with EPDM pond liner. Folks in warmer climates have to worry about termites when wood is in the ground, so it would be better to not use wood in the ground. You don't need much difference in height to have gravity do the work after the initial pumping, less than a foot per drop if you plan it well. Some downsides is that if you're wanting heated water you don't want the ground sucking all the heat out so the hole needs to be insulated. If the FT is lowest then the pump will chew up the solids so they are less easy to filter out if that's what you are trying to do after the pump. If your sump is lowest and the water level varies then many people have had sumps pop out of the ground due to ground water pressure when it rains heavily. In that case it's better to have the water level constant through constant flood or continuous pumping.

You can have a great system as just a FT as the lowest thing, pumping to a slightly raised gravel bed of copious size, draining right back to the FT, if the system continuously floods the gravel bed. If you turn over the water at least once per hour and the gravel volume is more than the FT volume and you stock relative to the gravel bed volume rather than the FT volume then that could be very simple and productive. Adding compost worms (red worms) to the gravel bed will keep the solids under control.

It looks a bit complex and possibly unnecessarily so. If you are going to run a solids removal stage I would just make it a swirl filter or a settling tank so you can drain off the sludge. You may find if you try and remove all solids in one smaller gravel bed with worms then it may clog and require you to remove and clean gravel. Unpleasant. You could go swirl filter then to a fines filter with orchard netting for removing the fines. This can be more easily removed for cleaning. Also unpleasant. You could just eliminate all the solids worries and just have lots of gravel surface area and worms and try to get the solids well distributed over the surface of the gravel for mineralization. My brick system goes from FT to GB's to sump on a flood and drain. So far I have had no problems with clogging although solids buildup around the inlets is a bit unpleasant if you feed heavily. I actually adjust feed according to how much solids are building up around the growbed inlets. I have also found that in some of the beds the worms have thrived and these beds stay clear of solids. Beds with poor earthworm pops have more solids issues. I would not be too hasty to put everything in the ground. Barrels and tanks are actually a real pain to put in ground. They collapse in and pop out and all sorts of issues. Its also hard to work with gravity if everything is in the ground. If its aesthetics then just make your stuff look better with cladding etc or build with brick and mortar which is really quite cheap to do if you can do it yourself.

Great news and info Dave. Thanks so much! I've added the insulation and am really not sure what to do about chopping up the fish wastes. Is there any type of pump that is gentler on the solids?



This goes against almost all my design goals (which may sound somewhat unreasonable... ). Along with making it beautiful, and fitting into our available space, we are hoping to design a system that will work for poor and indigenous cultures where it is out of the question to ship or require tanks, copious amounts of gravel, heavy duty timber and high power, expensive pumps with high failure rates, etc. etc.

We need to reclaim the solids to fertilizer the rest of the property which cannot be adapted to AP, minimize water turnover to reduce energy needs and evaporation and rely as heavily as possible on natural biological processes such as water plants in the ST that can become fish food, etc.

1) Does anyone know if Polyiso is a good choice for in-ground insulation, or how about dry-wall wrapped in plastic?

2) Will a bubbler work to raise the solids?

3) Has anybody got a study on what plants make best Tilapia feed and remove the most Nitrates beyond duckweed? Anybody working with chlorella, spirulina or blue-green algae which could serve as an alternate people food?

Thanks ever so much folks. The info and support has been fabulous!

Thanks Brian. This is great inspiration! I am working on a custom design integrated SF/BF. See second-try drawing below for everyone to either celebrate or poke a bunch more holes in...


Decided to just dig the sump tank in. Cheaper, and no barrel to pop out.

Why have you got two threads on the same thing?

Hi Jorgy,

Sorry for the redundancy. It really is two threads... Started it in new member introductions and quickly realized it was going to need a new home over here. Been getting some great conversation in both places and keeping both conversations going seems helpful at this stage.

Hoping this is the right place for it to eventually land and develop into a working and beautiful home system!

Hi IV:

Can you list your constraints succinctly? I didn't know about the developing world constraints.

A classic gravel bed system is about as simple and cheap as you can get, and can be done with just two holes in the ground and one pump if that is what you want. The gravel bed with worms and bacteria and plants in it handles everything but the housing for the fish. Two containers and one pump can be a complete AP system, then the remaining options are about how to contain the water and gravel.

Drywall has no insulating capabilities, an air lift (search "air lift" on the forum should find a lot) can work to move water a very limited amount (like a few inches at most).

The reason to turn over water at least once per hour is to maintain good water quality. You can look at reducing the power requirements but to paraphrase Einstein you will need it to be efficient but not "too" efficient. HTH

Doesn't sound much like AP to me. Maybe you want to raise fish, remove the solids and add them to a soil-garden... then change the water out regularly and water the soil garden. I guess most/all of the conversion from ammonia to nitrate would be done in the soil at that point. It seems to me that would fit your needs better.

Actually, at that point maybe just omit the liner in the pond and the soil would absorbe the water/nutrients direct from the pond... Okay I have no idea what I'm talking about.

Hmm. It looks a bit more logical now. Draining solids sludge from the solids removal and biofilter thingy will not lose you too much water. Possibly not necessary to try and filter it and return the water to the system. Why do you have it going both to the sump and the fish tank from the bio-filter sludge scrubber? I would ditch that aspect. You can run the solids sludge to an earthworm container where you can have earthworms to consume the mass of organic waste material that is produced in the system. You need to have some kind of composting arrangement. Just a compost heap with worms is great or a wormery. If you want a good looking system I would avoid all bio-filters and swirl filters unless you have a way to hide it away. They are pretty ugly things mostly. If you are designing for poor developing cultures the simpler the better imo. The less components and points of failure the better. Even the Rakocy UVI system which is a fairly complex system runs on a single pump. A sealed pressurized bio-filter sounds to me like a bad idea. Just run the water to the bottom, swirl it there and have a drain. Then it flows up through the media and out a exit point under gravity it goes on to the growbeds. Pressurizing will only give you more issues with sealing it up. In an ideal world your bio filter media should be able to be removed for cleaning quite easily

You probably can find a suitable substrate local to the systems your installing.

I feel I have to point out that the current design has way more tanks than it needs - You could just use an in ground growbed with integrated sump (when you get into high stocking desities with the fish then you'll have to worry about excess solids clogging the growbeds. Worms will take care of most solids in low to medium stocking densities). You could have multiple growbeds all joined with a common sump. The sump would have a single pump to pump the water back up to the fishtank which is the high spot.

I'm assuming the 200 sq ft of growbeds are only one foot deep - they could be deeper and give you more filtration capacity.

I'm not sure what to suggest on the pump, it really kind of depends on what you consider acceptable operating costs and failure rates.

My current pump uses the same energy as a 100 watt light bulb to run a system with roughly 800 gallons worth of tanks. This is more than adequate to get the necessary turnover. I've only been running this pump for about 5 months but no problems so far. I always have a backup pump.

Re: pump failure. I've had pretty good luck on this. My old RIO 2100 is still running after going for 4 yrs worth of hydroponics and aquaponics during a 6 year period. Most of the other pumps are small and have only run intermittantly, all are still working. Something clogging the pump is a common problem. Look for a solids handling pump, this will help.