Backyard Aquaponics
A place to discuss aquaponics

Insulated integrated growbed and sump

OK, I will probably be sorry about this test system. Two days and I've already found a few things that could be much improved. Still, this is my second-and-a half system and my first system post.

This started as my first system: a 50-gallon (a bit under 200 liters) aquarium, a 3-cubic foot (uhhh....85 liter) growbed mounted in the window, and a few goldfish and mosquito fish back on January 24th. Got a bit of slime off pond and creek rock and washed it into the gravel filter to get the system cycling fast: maybe a week. Within two weeks I couldn't stand it any more and added about 20 crayfish (about 2cm to 4cm). They grew fast (the largest goldfish reached 3 or 4 inches and so did the crayfish). Due to crowding, I decided to eat several of the crays (quite tasty) on February 3rd, leaving a few to breed. Everything seemed pretty stable, although I noticed a few sudden changes in behavior of the residents and of the growth and type of algae on the shells and rocks.

Anyway, things were going fine, but on April 3 I added my 25 male tilapia and a heater. Those buggers really eat! And I believe they produce a mucous or slime: my growbeds immediately began clogging far worse than they had ever done previously, but we managed. Anyway, with addition of a bubbler and various changes to the growbed I've continued to this point, but disaster was clearly looming due to pushing the limits. Time for a change, even though I wanted to do some testing first...oh well...brace yourself for system 2.5 (what about system 2? Uh...that is not really interesting...pretty standard stuff).

I don't have room indoors (roughly 450sf (42 sq meter) home for 3 people) nor would our floor handle a large load nor do we have the light for plants: this filter goes outdoors. So, temperature fluctuations are an issue: I really do not want to lose or gain too much heat. We have really dry air and strong afternoon winds, so the dewpoint is around 50F (10degC): evaporation is a major issue. Summer temps average about 65F (say 20C) and I want to hold temps around 80F (27C). Landlord doesn't want a greenhouse and, anyway, the wind might rip it down. Space and visuals are issues, too.
We came up with a typical-appearing planter for the one sunny spot near the house. The planter is 30" tall (75 cm), 8' long (240cm) (6' usable), and 30" deep. The gravel bed is 12" (30cm) deep, there is a 16" sump underneath that, and at the end is access for pump and drain mechanism (adapted from Travis and barrelponics). Plumbing is run with no low points to block startup flow if power should go off and then restart (thanks for the heads-up there, KP). So far temps are doing ok with a 200W heater (actually increased slightly in 24 hours), but with some insulation on plumbing and some to block evaporation from the sump we should do far better....maybe even keep temps reasonable for tilapia in the winter with avg temps around 45F (7C?).

The fish are really, really happy now with the high aeration, high flow (3GPM or 10liters/minute), and clear water. Some fish chow, some algae, some water fleas, some bubbles to play in and they are happy campers. Big improvement over the previous 1/2gpm (2 liter/minute) filtering, even though that kept the ammonia/nitrite down to zero. I've kept the old filter in place while the new one cycles and might just keep it planted with ferns, etc.

Notes:
I really, really should:
1) use heavier or more layers of polyethylene in the sump: it will be miserable to repair if it gets a puncture, but it is well protected, so I'll cross fingers. EPDM? But so expensive....and I'm so cheap. *grin*
2) Have a shutoff or other overflow preventer: if the algae I feed as a treat clogs the overflow, we will have 200 gallons of water on our kitchen/living room floor, my DW will not be pleased, and I will have a whole lot of cleaning to do, and the plants will have lost their nice rich water.
3) make backups for the system pumps...maybe even two pumps in case one fails.
4) change layout of flush valve and access hole to reduce space taken by the lid.
5) insulate the sump access at level near bottom of gb: the lid is soaked with condensation in the morning.
I really, really like:
1) seeing the fish and their behavior: far better than any top-view container. But how to increase production?
2) the toilet flapper rather than auto-siphon. Don't get me wrong: I love the a.s. as it takes up very little room and is beautifully simple. On the other hand the flapper can work with less than one cm of height differential from bottom of gb to top of sump, drains fast, and, with Travis's bottle-flusher, can be made to stay open for minutes after draining is complete (ensuring more complete draining when solids have built up...this is an issue with my indoor windowbox growbed).
3) high-volume sump: really, really stabilizes water quality and temperature.

My thanks to all here: I would have far more errors and problems without the experiences you have shared.

Construction was good fun....although support may be lacking: we shall see if it sinks into the clay when rainy season comes in several months. Anyway, here are some details....

OK, last pictures: growbed and drain valve details. It has been a long time since I got to play with hot stainless steel rod, so I had some fun with the flush valve mechanism.

So this is a flush valve setup ala "barrelponics" but in the bed to flood and drain....

Kind of like Elk's in growbed siphons... but float valve operated rather than solenoid....

Neat Hydrophilia..... how reliable do you think it will be?

Are the rods stainless steel?

Yep. Love stainless..



That is a really, really good question. Wish I knew.... So far (9-days in) I've had two failures where the valve failed to close, both in the first 24-hrs. Once was due to the bucket getting pushed in a few mm and touching the flapper valve (solved with a pvc tube brace). The other was caused by the bottle falling too far during a flush and jamming, so I added a rod across the tube to prevent falling too far and to prevent it getting too far off center for any other reason.

I like the solenoid idea and it might take up less growbed and be more reliable (...hmmm....wonder what their mtbf rating is?). Maybe next time... Still, I tend to go with mechanical: you should have seen the door to the chicken house that operated by the weight of the chickens on the roost.....but the roost moved too much and scared the chickens after a few days *sigh*....electronics would have worked better.

Sh*t - it even says so in your post, sorry

As far as siphons needing a big fall part - no they do not

Well done on designing your valve, be interested to see how much the insulation helps the temps.

DOH! I meant to post explanatory pics:



Mate, you are a better man than I if you can manage an autosiphon that will work reliably when the drop in water level at the finish of cycle is less than 5cm. Mine tend to slow as the levels become closer and, occasionally, simply turn into unintentional flow-through systems. Now, with a drop of half-a-meter it starts and stops with some real authority! (wait a minute...I forgot that system, the one with the hot-tub as a growbed ...that makes this one the 3.5th system.....*grin*)

I just bought some scientific thermometers: larger range and more accurate than hardware store or lfs. I've got to get some real numbers on heat loss....I'll try to post some results in a week or two...

Cool, love the aquarium a lot! The satellite planter box is cool too - what are you going to grow in it?

You might try a water bridge/no holes overflow to make sure that water doesn't spill over the edge in the house. They need a little maintenance every few days to make sure that a bubble doesn't shut them off but otherwise it would work for your aquarium here.

viewtopic.php?p=125191#p125191

Thanks, we love the aquarium as well. Sometimes the TV stays off while we just relax and enjoy the peaceful fish play in the current and bubbles.

So far the DW has herbs and squash growing. I've been thinking about adding beets tomorrow.

I like your water bridge pipe, especially your touch of upturned ends (will help keep bubbles out); sort of like Nick C's(?) clear box. Am using something like it and have been thinking of ways to slow the clogging (a filter on the inflow, a second intake above normal water level) and buildup of a fatal bubble in top of loop (a double-valve standpipe or a single clear standpipe/reservoir to collect bubble harmlessly for a time).

OK, I just posted, uploaded, and lost it all while pic was uploading. Dang!
Let's try again:

Fish are still happy and growing, but we have had a heat wave here with daytime temps up to 100degF (38degC) and fish tank temps are up to 84degF (32C), so I uncovered the sump this am and placed a fan blowing into it. Tank temp dropped 2degF (1C) in a couple hours. Largest tilapia are near 5.5" (14cm). They seem to be less active than when I first added the new growbed and more flow: perhaps due to larger fish, perhaps due to lower aeration due to lower pump flow.

Pump flow is down to about 1.5gpm (5 lpm), probably due to buildup inside pipes adding to friction. (is this reduction in flow a common problem? What are your solutions?) Next time I'll go with larger plumbing to give me less friction and more time between needing to flush pipes: maybe 1.25" (32mm) rather than 3/4" (19mm). It might be really nice to have a few strategic valves as well so I could flush both lines (fill and drain) in one shot rather than separately. I've also found that flushing pipes has added to water level and my sump is nearly full, less than two inches (5cm) from overflow. Lots of mosquitoes in there, probably looking for a place to lay eggs, so I'll keep an eye on it, add a fish if I must.

Plants are doing well. The new squash leaves are larger and greener than the ones they arrived with! Basil and parsley are very happy. Beet seeds sprouting. Other herbs doing ok, but nothing spectacular. I need some plants that stay low (or can be cut low), like heat and sun, and that my DW would enjoy for kitchen....herbs, greens, etc. Any suggestions? Low height is important as she does not want window blocked! Lettuce will be wonderful when weather cools in October, but until then...

Note: scale in fish pic is inches, not cm: my apologies to all of you used to sensible systems.

The reduction in flow is very normal

Bigger pipe is what you need, even 25mm gets a decent flow reduction once biofilm builds up.

Here are a couple pics of plant growth over about a two-week period. This is pretty darned good for around here as we have chilly mornings, then windy hot afternoons, then fast chilling in the evening before the wind drops off. Ignore the parsley (back right) as it has been heavily harvested and the sage (front, just left of center) as I planted it yesterday. The squash, basil, parsley, and beets (from seed, front center) are doing great. The others are doing well, but slower.

My dw planted the summer squash in the dirt garden as well, where it has been competing with weeds and not getting proper irrigation (yes, I hear I should do something about that..). The one in the garden has all male flowers while the AP plant has had one male flower out of six to date. Makes sense....

One thing I really am finding attractive about flood-drain is that the plants get plenty of water and plenty of air to their roots. Some that would suffer in the garden on a hot day do fine here.

The root temperature is also more stable than in the garden which keeps the cilantro from bolting to seed. I expect the other plants like it as well.

Dw is really liking the system so far. Le frog is staying happy as well and no more sign of mosquitoes.

Those are some lovely fish!

Be sure to check on your string often as it will likely eventually deteriorate and break. Keep some extra spare parts for your flush valve in case something wears out.

Lets see, useful low growing plants. Perhaps Oregano, Thyme, Stevia, and probably many other herbs (beware mint will take over the bed so is best restricted to it's own domain somehow.) Lettuce, spinach, kohlrabi, turnips, radish, spoon mustard, mustard greens, cabbage, and many others will be good once the weather cools. You could probably train a tomato plant around the edge or to hang down off the grow bed or perhaps train up past the widow and prune off any of the foliage that blocks the window. Onions seem to do fine in AP. In cooler weather there are pansies, violets and violas that are not only pretty and low growing but edible. For the warm weather you might be able to grow Nasturtiums that are edible (kinda hot and strong tasting though,) pretty and would look nice hanging over the edge of the planter.
Sweet potato can be low growing but might be too much for such a small space, they like hot and wet though.

If you have a shady spot, I've found that aloe will grow fine in AP but they can't take lots of direct sun.

Looking good! Keep it up.

Thanks for the info.

I've been keeping an eye on the mechanicals and, after initial modifications after some HSMs (near-flood, etc) have modified for stability. Major item is to have a high intake in the aquarium in case low one gets blocked! The string is synthetic and kept in shade and checked frequently (and time will never decrease my vigilance and make me complacent.....yea, right.) I've thought that if one had a very large growbed it might make sense to have a double drain and double pump simply for redundancy...
And I always have a spare toilet flapper valve.

Your plant list is very nice. I'm trying sage, as I mentioned, although I heard it likes drier soil. Still, worth a try as gophers or something keep killing off what is in the garden. I'll try the rest of the list later.... I like the idea of sweet potatoes as something that would suck up extra nitrates and could be trained out across the yard. I'm forwarding the list to my darlin' to see if any pique her interest.

Our mint gets to struggle for survival in lightly irrigated dirt. We probably couldn't eradicate it from around the roses anyway! On a totally different subject: has you read "Greener than you think" in which the world gets taken over by improved grass, wiping out humanity? (Don't know why that came to mind... *grin*)