A few shots of the reef aquarium/inhabitants.
Reef aquariums (vs fish only systems) can be very expensive and almost always involve AT LEAST two tanks, if not more, as well as special lighting for looks, for beneficial macro/micro algae, and for other photosynthetic critters in the tanks.
One of the things with these types of systems is that you never stop learning. I'm eventually going to use what I've learned on this system to create a reef network at my place. The idea is pretty much the same as running a computer network. The hub will be a large sump, with an appx 800 gallon capacity.
Basically, a sump, at minimum, is where your heaters, protein skimmers, top off systems, drip (calcium, magnesium, iodine/iodide) systems, and mechanical filtration takes place.
The sump can also double as a biological filtration station, with live rock, live (deep sand) bed, and macro * micro algae.
The way deep sand beds work is that the first top layer of sand (some people claim up to 1.5") is full of aerobic bacteria the feed on ammonia and convert it into nitrite and then into nitrate. Further down the sandbed is anaerobic bacteria which feed on nitrates and release nitrogen gas, which builds up as bubbles in the sand, to be released out of the water.
Macro/Micro algae use excess nitrates and also take out phosphates from the water, as food/fertilizer. Protein skimmers take a lot of the organic wastes out of the water that haven't had a chance to break down and cause ammonia spikes. Live rock harbors various algae and micro/mini fauna (snails, sea stars, hermit crabs, oysters, clams, feather dusters, anemones, tunicates, bristleworms, etc) that also filter the water or feed on fish waste. Live rocks also harbor trillions of beneficial bacteria and does a lot of the same things live sand does. Beneficial algaes are beneficial also because they starve out the nuisance algaes.
A lot of people think that with a certain selection of cleanup critters, the aquariums will eventually get to a point where there is no maintenance involved. There obviously would be a point where there is very little maintenance, because reef systems are biospheres, but a proper balance would mean having a minimal bioload and therefore not a lot of fish in the system.
Lighting will always have to be replaced between every six and ten months, because they lose their power to grow plants and photosynthetic organisms. At around six months of usage, lights only work at about half of the power they had as new bulbs, and they steadily decline afterward. When lights are old, their beneficial algaes start to wither, and nuisance algaes start to take over. Live corals will start to lose their vibrant colors and may shrink and eventually die.
Back to my system and plans for the reef network....... Right now, my reef system (55 gallon) has a deep sand bed of about 8-10", probably about 200-250 pounds of sand and another 250-300 pounds of live rock in both the main display tank and sump. The current sump is 20 gallons. I'm currently in the process of setting up a larger (30 gallon) sump a separate (20g long) refugium, as well as a 20g auto top off system. This will give me 30 more gallons of bioload capacity.
Most people setup refugiums in their sump, through a series of baffles that make water go over, under, and over. Unfortunately, there is a maximum allowable space underneath the tank stand, and a 30 gallon tank is the largest that will fit. Also, I put nuisance animals in the sump, like the huge xanthid crab pictured above. He probably wouldn't be too kind to some of the life/critters in the refugium.
This refugium will use macro algae, mainly chaetomorpha, to filter out nitrates and phosphates from the tank, along with a deep sand bed, and various oysters, clams, tunicates, some corals, and feather dusters to filter the water. A few snails will be added to keep the sides clean and sandbed sifted/stirred. This system will have a metal halide lighting system over it the photosynthetic stuff. It will also have a gravity fed u-tube overflow system.
One of the problems with all of the live sand and live rock in this current reef system is that even though it filters like crazy, there isn't a whole lot of room for fish to swim between the rocks and glass. Basically, this system has 2 monos, a columbian shark, an orange chromide, a knight goby, a flagfish, and two dragon eels. Out of these fish, the columbian shark (grows to 24") and two monos (grows up to 18", usually only around 12" in captivity) need a much larger tank even without all of the rocks and sand. The dragon eels (up to 24") could very well outgrow the tank too. So, these guys will have to go into my reef network when it is completed.
The whole idea of the reef network is to share a filtration system with a network of aquariums. The reason why I'm going to go with an 800 gallon sump is because I'm going to have a shark tank, somewhere around 180-300 gallons, and sharks not only produce a hell of a lot of waste, they also need almost pristine water conditions. More water = larger bioload capacity.
If everything goes according to plan, the shark tank will actually be placed along a wall in my dining room. There will also be either one tank or a series of tanks in my new living room addition, at least 180 gallons.
In various rooms of the house, I will have smaller tanks setup. They will all have a gravity fed overflow. There will be check valves to prevent siphoning and ball valve switches to control waterflow to each tank.
Heating a system like this would be no problem, because every pump, powerhead, wavemaker, and light produces heat, as well as the heaters themselves. In many cases, the equipment will heat up the water enough to prevent the heater's thermostat from kicking on. Even in the winter time, this should be no problem.
Cooling the system will be the next challenge. Most tropical reef systems need to be between 78-84 degrees. The same lights and equipment, and even the summer itself, produces a lot of heat. Getting an aquarium chiller rated at around 1200 gallons would be ideal, but a smaller one may be a viable option, with the addition of a radiator coil system.
Evaporation and humidity damage is the next step to prevent in such a large amount of water and also has a little bit to do with the added heat in the system. There are two options to control this: #1: put a ceiling vent above every open-top aquarium or #2: use closed top aquariums.
Open top aquariums obviously are going to run a little cooler with lights, but the water evaporates faster and can cause humidity damage in the home. If there are no photosynthetic animals in the aquarium, then it may be possible to use an LED lighting system with a closed top.
Closed top systems, when used with metal halides, or even strong power compact bulbs get very hot. Less evaporation but more heat. Since cooling a system is harder to do and more expensive than heating one, closed top systems with photosynthetic critters are just undesirable.
There's a relatively new trend now days of using skylights as replacements for metal halide bulbs. The initial costs are usually pretty expensive, but in the long run, it's actually cheaper than replacing expensive bulbs every six months, and they would pay for themselves in just a couple years I would think, not to mention the huge amount of electricity metal halides use. Skylights produce much less heat and use the natural sunlight for photosynthetic creatures. It's one of the two new eco/green ways to enter this hobby.
The other eco/green lighting system is LED lighting. Using a series of 1-2 watt 10,000k led bulbs, it is said that one can run a reef lighting system with only 25-50 watts for a 48" aquarium, compared 500-800 watts for metal halides. LED reef lights are new to the market and really haven't been shown to be as effective as metal halides for some of the more light-intensive coral species. They're also relatively expensive compared to say power compacts and t5s.
I'm a fan of eco/green stuff, and marine systems probably have some of the worst press about how much energy it takes to truly run a reef tank, mostly because of the lighting. One of my things with running tanks is to use u-tube overflow systems that are gravity fed with no electricity usage whatsoever. A combination of skylights for daylight 10,000k range lighting and blue leds for actinic lighting would also make a nice eco/green statement. Even if LEDs haven't proven themselves for photosynthetics, they can make an aquarium look nice, and many also emulate the shimmering effect of metal halides.
It's hard to say exactly how the final plans will be on my reef network, but I'm definitely going to be looking into using skylights for the 800 gallon sump system and LED (or other low-power) lighting for any tanks that don't have photosynthetics in it.
My shark tank will be a fish only system with a small layer of sand on the bottom. It'll probably be a bamboo and/or horned shark, because obviously, I don't have money/space for a 100,000 gallon great white tank! It'll either be a custom built (plywood/fiberglass) tank with glass only on the front, or a pre-built tank with a painted background and will have multiple wavemakers to assure lots of current like the sharks need. These will share their tank with my monos and columbian shark, until if the cat shark gets big enough to eat them easily.
The living room tank, I really haven't even thought much about yet. Most people get a couple large fish (tangs, butterfly fish, angels, triggers, etc) and they produce a lot of waste. Of course, my filtration system should be able to handle the waste without any problems.
Building a reef network also means that I can setup smaller, nano aquariums in possibly every room in the house, for those smaller fish, like the firefish goby. basslets, small blennies, clownfish, etc.
The shark tank will have to have a special kind of sand, one with super fine round particles, because their bellies get scratched up and infected relatively easily, causing a lot of deaths in aquariums. It is illegal to collect sand on the beach or out of the ocean, and having this special sand shipped can cost $1 or more per pound.
In the case of shark tanks, it's probably best to get dry sand, because wet (live) sand weighs a lot more, and for the 1" of depth we'll need, it'll probably cost between $200-$300 alone.
I'm just guesstimating, but I believe the reef network system will need somewhere around 2,000 pounds of sand and probably 2,000 pounds of rock. Most of that sand can be bought dry in square yards via a landscaping company, washed well, and mixed in with aragonite sand and crushed coral to act as a PH buffer for probably less than $100 total. Just like the sand, you can use dry reef rock as well. Unfortunately, good dry reef rock here is actually more expensive ($2.50-$4 a pound) than I can get live rock shipped to me from Fiji. The cheap live fiji rock is probably mostly dead due to it being shipped out on boats for 2+ weeks, but the dieoff will make the tank go through a cycling process, which is has to go through anyway when it's first being setup. You just don't want to add live rock to a system that's already cycled. What really livens up the rocks is when you add real live rock, like for me, gulf live rock which is harvested in Florida and shipped out quickly. The various algaes, worms, and critters spread throughout the system over time.