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Here's the project:

To convert a small garage into a fish house holding my own design of breeding tanks, growing tanks and barracks.

I have opted to use plastic storage boxes for the tanks, as they are light, easy to work and cheap. They will also lend themselves to easy modification for filter screen insertion and cutouts to allow water cascade from one to the next.

The design of the first rack will be something like below:


The water will cascade from one tank to the next down to the sump, where it will be filtered and heated before being pumped back to the first tank in line.

Each row will have it's own sump, and each tank will hold around 15 gallons. The number of tanks in line will be dictated by the length of run. I anticipate having runs of 8 tanks plus the sump, giving a total water capacity of 135 gallons per row. This will give me 24 tanks on this rack and a total fish space of 360 gallons. The economics are simple. It will only require three 300W heaters and three pumps to maintain the entire rack!

The sump design will be simple, with a floss filter and gravel initially. As this is only going to be used for growing out, there shouldn't be any further filtration requirements. Water changing will be done from the sump, avoiding the need to disturb the fry at all. Power outages will not cause any problems either, as the water will not be able to overflow any of the tanks or the sump.

Attached Images

rack1.jpg (40.2 KB, 44 views)

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I have 2 ideas for the cascade:

1. a full width filter screen made from plastic netting, like you use for crafting rugs etc, fitted into a rigid frame that just slots into guides in the tank and then use 1 1/2" plastic piping to drop the water to the bottom of the next tank inline;
2. To use the above type of screen and just make a cut-out in the side wall of the tank, so the water just cascades over the side to the next tank .

Questions:

Idea 1 seems the better of the two, but is more expensive. Idea 2 is cheaper but more prone to leaks and puts the water onto the surface, rather than forcing circulation.

Ideas folks?

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The sump:

Here is the outline design for the sump. It will need to handle about 100g per hour throughput. Is it workable?

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sump1.jpg (17.4 KB, 28 views)

Dino

You will need something to get the water moving down in the vats.
Current design will only move surface water.

Use a heavy a grade of plastic tote as you can find.
Lighter weights will bow/bend with the weight of the water.

Cascades will leak.
You need to add a lip to the overflow over/into the next one in the line.

Thats all that comes to mind at present.

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I did think about the water circulation in each of the tanks, which is why I favour idea 1, which will drop the water into the bottom of the next tank, forcing it to circulate, whereas the cascade would simply run into the lower tank and move perhaps the top inch of water. It wouldn't be difficult to have two feeds from each tank, one each end, to increase the current.

the containers I have in mind are the stackable type, which are very strong and actually have 110ltr capacity, slightly less than I was planning, but still quite sufficient. these are a clear plastic with reinforcing on the long sides. It would be possible to arrange these end-on, so they take less room and have the outlet at the back running to the front of the next, or the other way about. This would force a current right through the entire length of the box, from the bottom to the top. By dropping the outlet as low as possible in the next tank, it should increase the force with which the water falls too.

I also have the idea of introducing air bubble wands to each box to help with circulation.

Marc

Perhaps you could look at the wide-end vacuum attachments for what to use with idea #1.

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ok, here is the trial setup:

3 boxes as image 1 (7g)
2 filter grills, image 2
2 fittings and pipe, image 3

I am going to put this all together above the 8' tank, to make sure it all works as planned. I can pump the water straight from the 8' into the top box and just let the bottom box drain into the tank below. It will give me an idea of whether the system works and how well it operates, as well as giving me another 3 growing tanks for the time being! (No need for additional filtration either, since the water will already be stable)

I'll post some pics when I have it set up.

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	bin.jpg (81.0 KB, 7 views)
	grill.jpg (113.3 KB, 9 views)
	fittings.jpg (94.2 KB, 6 views)

atmmachine816

Depending on the fry you might have jumping if you don't have lids?

Kevin

some body might have already suggested this, but what if you connected the tubs with a pvc pipe...covered with soft mesh...about midway down, along with the cascade, and bubble wands

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All the boxes come with removable lids as an extra, if I need them, which I probably shall!

The problem with plastic is that it bends under pressure, which would lead to leaks on any join or connector mid-way, unfortunately. I had thought of having that sort of screen to allow the water through, but the side panels don't meet, and any pressure would just break the joint.

Kevin

yeah...i didnt think about the pressure
you could always use duct tape

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hehe

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The trial tanks are filled and working. The flow isn't terrific, but that's because the pump I'm using isn't the strongest, but for a trial run, it seems to be doing the job. Circulation isn't a problem even with the low output pump, and the water is moving as I had hoped it would, and is spiraling up the tanks from the outlet to the intake. I found this out by using meth blue to color the water and watched it's progress. With a stronger pump, the circulation from tank to tank and within each tank will be fine!

The flow rate on this setup is about 60g per hour and the currents within the tanks are not too strong for the smaller fry to cope with. Addition of airstones will further help the currents by putting them in the corners. 2 stones per tank would be brilliant! (Just have to get hold of some more air pumps!)

one problem that has already shown itself is the corner screen has broken away from the side, so the final ones will need something better on that joint, or more time to cure!

it has helped to prove the design, and i don't see any major issues with the full blown rack, except that the flow pipe will need to be bigger to cope with the volume. This is using 22mm overflow pipe, the final setup will need to be 1 1/2" waste. That might prove problematic on the fittings, but I'm sure they can be found.

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Here's what they look like now:

BTW, I was wrong, when the tanks are filled the sides DO meet!

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	filledblue.jpg (75.6 KB, 28 views)
	filledbluesideon.jpg (67.9 KB, 17 views)

susitna-flower

neverendingninja

Excellent idea, and very good craftsmanship! I'm impressed, but unfortunately can't offer much advice other than to keep up the good work and post plenty of pictures along the way.

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It's in the overall plans, but probably won't happen for a while. The water changes will be minimal, since each run will have 405 ltrs (107 gallons), it shouldn't need very much in the way of changes. there will also be ample space in the sump for plants, which might have a similar effect to the aquaponics!

In winter the temperature rarely drops below freezing, and the fish house will be insulated and heated, so I don't foresee any major problems with a stable temperature, but don't want to risk the temperature dropping too quickly, hence the heaters in the sumps.

Water changes will be easy! it can all be done straight from the sump. All I will need to do is connect a waste pipe to the outlet of the last tank to divert the flow from the sump, and fill the sump with fresh water! could it be any easier?

I will be able to do water changes in about 15 minutes, instead of 2 hours! The current that the water creates will keep the majority of the debris suspended, so the tanks should stay pretty clean on the whole. Maybe have to spend half an hour a day with a gravel vac in the tanks, but still not a major issue. All the tanks will be bare or minimal with maybe a few silk plants and rocks, but there won't be any gravel to worry about.

Don't worry.... there will be plenty of those!

atmmachine816

I'm just curious, what did you use to make the holes in the containers.