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The Palanggana System (palanggana: Filipino term for washbasin)
My reef system is simple, cheap, and stands up to the very considerable effects of Philippine weather and climate.
The grow-out tanks are basins. These provide a large surface area with respect to water surface and bottom, for better stocking capacity and lighting.

These basins are equipped with a surface-skimming overflow, and are arranged in descending height.Water moves by gravity downflow from one basin to another and into the lowest basin, which is filled with live rock.

Thence it drains into the sump which contains a foam fractionator (protein skimmer) which is technically in-line, and a powerhead pump to return the processed water back via pipe to the topmost basin in a fairly straightforward cycle.
Biological water processing is done by the live rock while the skimmer removes suspended organics.

 

Lighting is natural, as my geographic location is ideal regarding light. It is farthest from ideal regarding temperature. The sump is shaded, and the basin sides are protected with opaque insulation. An overhead sunscreen/rainshield reduces the effects of the intense Philippine sunshine and the robust Philippine rainfall.
The System at a Glance
Materials Used   Location and Assembly Notes
The grow-out basins are ordinary plastic washbasins, cheap and durable. They hold about 25 litres each, which isn't a lot and therefore doesn't cost a lot saltmix-wise -and I DON'T scrimp on the quality of the salt. The overflows are PVC elbows with a very short piece of pipe in one end.
The basins are protected by covers of plain clear PE plastic sheeting. These rest on a crosshairs of nylon fishing line tied into holes drilled or melted into the basin rim. The cover sheet is held in place by nylon or wire-tie 'pegs' also tied into basin-rim holes, and through holes in the cover sheet. The cover sheets are cut to allow for overflows into their basins. The sump is similarly covered.

The sump is just a plastic bucket with a plastic handle. It holds about 25 litres of water. It sits on the ground, shaded by the table-frame on which the basins rest. (We'll get to the table in a minute).
The last basin drainpipes into an elbow which enters about halfway up a plastic mineral-water bottle with its bottom cut out. With a wooden airblock (powered by an airpump of course) inside the bottle, and large-bore plastic tubing tightly punched through the bottle's cap, we have a very simple home-made foam fractionator.
A venturi powerhead can be used in lieu of the airstone. The mineral-water bottle can be fixed to the side of the bucket's interior with suction cups or just weighted with rock and rubber bands to sit on the bottom. Out the bottom of the fractionator, the water enters the sump proper.
The return powerhead is standard. I found a 1/2" diameter PVC female threaded adapter (they aren't all made the same) that perfectly fits the exhaust port of an Aquaclear 201. this made for a flawless segue to the 1/2" diameter PVC return pipe back to the first basin.

The table is of 2x2 wooden construction, and fairly simple to make if you have any carpentry skills. It has to be well-braced and well-sealed (with paint if you like). On the table, small platforms of sealed 2x2 wood and plywood allow for gradations in the height of the basins.Overhead, a rainscreen of clear heavy-duty plastic (if you're rich you can spring for polycarbonate) coupled with a sunscreen of blue plastic netting tempers the elements. Likewise any appropriate thermal and optical shielding around the basin-sides and sump.

 As this system is so bare and openly reliant on natural sulight, location is terribly key.
I'm an architect, so I had it easy: I built the damned location. Hard by the firewall on one side of our home, I installed a high, decorative trellis. This supported the sunscreen and rainscreen. Under it, I had a concrete slab poured. Electrical outlets were installed, and a water faucet tapped in. I took into account solar angle and pathway, so that the house would not shade the basins too much or too little --throughout the year.

Assembling PVC plumbing is easy as long as you measure everything out with exactitude. Once a coupling is glued in, it's fairly permanent. the glue emits toxic fumes, so take precautions.

Drilling anchorage holes into the basin rim is easy if you DON'T drill: just melt them. With a pair of pliers, hold a 1" common wire nail over a candleflame, and then melt holes. If the nail cools, then reheat. This of course works with PE basins and buckets. With certain other thermoset plastics, you're better off using a drill. Melting plastic can give off fumes, so take precautions.

The overflows are trickier. The hot-nail technique can be used to trace out the hole in the side of the basin, or you can use a soldering iron to trace and melt the hole outright. It IS tricky. And melted plastic gives off fumes, so ...you know the drill.
The overflow elbow/pipe must then be fitted through the hole, and then the joint thoroughly sealed with silicone on either side of the basin-wall. Silicone isn't toxic, but it's real messy. Some coat their fingers with liquid soap before smoothing out the silicone gel so it doesn't stick to the skin. I just let it dry on my fingers and obsess on peeling it off later.

Don't forget the other peripheral equipment you'll need to maintain and monitor the system: a hyfrometer to roughly gauge the salinity of the water; an extra bucket for mixing saltwater; a thermometer to tell you when to start panicking. A flexible plastic hose (pretty large-bore!) or open gutter that can fit onto the outlet of the return pipe is a big help if/when you have to bypass one basin or another. I have never had to, but a leak is always a possibility.
Support Livestock
Apart from the myriad lifeforms that come part and parcel of the live rock, there are a number of useful creatures you can stock the basins with.
I deem most herbivorous snails (except maybe Trochus sp.) too fragile and too clumsy to enlist in the war against unwanted algae. Sacoglossan slugs are even worse against the heat.
Young sea urchins of the Genus Diadema have given me the least trouble: they are too light to knock most anything over, and are deadly efficient at removing ALL surface algae. When they grow too large, I either give them away or can return them to their original home: Ligpo's reefs.
A lot of friends have suggested inclusion of fish, but I feel the basins are too open to give most fish any feeling of security. I HAVE hosted fishes from time to time, for weeks (often due to emergencies with friends' tanks) and the system can handle the load fine. The fish just get real jumpy (literally) with me leaning over the basins.