making a huge tank

[chris brown]

I am planing on doing a huge tank in down stairs of my house(over next few years) i have plenty of room to play with and was thinking of doing a 3.5m by 3.5m square 1m ish deep.
any heating advice would be great was thinking spa pool heaters-motors
i will be using plywood on the side and bottom with fiberglass over it. Was also going to put fibreglass on the lid or ceiling (will be ceiling height)it will have to be sealed to stop moisture getting into the house but will have 2 vents going to outside
i was thinking of something like this
http://www.youtube.com/watch?v=wGRFLZErAWg

any tips would be much appreciated

[UVvis]

If you are building this from scratch, you could easily add insulation to drastically cut back on heating needs. Once at temperature, you could probably get by with one 500 watt heater if you have it insulated well. Two on a controller would work well too. Plus, as the tank gets larger, you have less surface area to volume compared to smaller tanks, and with insulation, the lack of heat loss might surprise you.

If you are going to seal it the way you describe, with outside vents, make sure any filtration pumps are submersible. When you start going to larger and larger pumps, you can run into gas entrainment issues and run into emboli problems. You will also have to watch water changes as most tap and ground waters are supersaturated with gas.

Also, to make life easy on yourself, plan to have a standpipe with a dedicated drain line for water changes and a tank and or sump overflow drain to waste. This way, you can start a water change and not have to worry about emptying out the tank on accident. The dedicated drain being right there is also handy to have a gravel wash siphon going to it. Then if you plan to have your new water go through a good carbon filter, you can pretty much add it into your sump to refill the tank. This also would give you the option of turning on replacement water and letting the overflow drain the old water. The downside to dilution water changes is temperature differences and they are not as economical than drain and replace water changes.

Some good planning ahead for maintenance really cuts down on labor time involved later on.

[chris brown]

yes i am building from scratch and yea will definitely be insulating not sure what 2 use yet would normal pink bats work? behind the fibreglass and plywood or would that tin foil stuff be better? here is a link of the structure from that 1500g tank i would do a similar structure to this
http://www.monsterfishkeepers.com/forum ... glass-tank

As for heater, it gets pretty cold here over winter -7 was the coldest this winter but i am not 2 worried if i have to run 4 or 5 500 watt heaters scattered around the tank to keep it warm

emboli issue (2 much oxygen in water?) would using clean water from my outside pond fix this problem or would that just help introduce disease?
i will be stocking it with lots of clown loaches and few other loaches which like high oxygen levels discus and angels etc.
would running a fan on the vents help?
what other solutions will fix this problem?

i have been looking into filtration and have space in the next room to run a sump and overflow setup the guy that has the 1500g seems to have it sorted there to mite just copy his setup
thanks for the help

[UVvis]

You aren't planning for your tank to be outside are you? Heating wise, it's just a matter of having more input than output to maintain your set point. Insulation helps slow the heat loss. As a quick comparison, take a standard 10 gallon versus a standard 55 gallon. The ten gallon tank has 112 square inches per gallon, the 55 gallon has 67 square inches per gallon. Roughly... Point being, as volume goes up and you keep a normal dimension, your volume to surface area gets more favorable for minimizing heating/cooling loss, and your temperature swing will be lower due to the size of the system. Add some insulation, and you start finding that you can get by on a smaller heater than what you were expecting.

So, as long as it's durable, and you have the space, you can't really overdo insulation. Honestly for what you are talking about, doing it right up front can save some money and headaches long term.

Most people don't really think about it, as it doesn't apply as much to small systems. As the size of the system goes up, you use bigger pumps, more filtration, with more flow and higher operational pressures. You can get leaks on the suction side of your pumps/plumbing which can force air into your water stream. Since atmospheric gas is around 80% nitrogen and argon, you can saturate your water with nitrogen which will cause bubbles in your fish's tissues. Think of a diver getting bends, or how tap water or soda will have little bubbles form on the glass, same thing. Oxygen can be metabolized so it isn't worth worrying about, and the CO2 usually just enters the carbonate equilibrium in your system and drives pH down slightly, so not a huge concern on those two comparatively. When you start moving water in the gallons per minute range, versus gallons per hour range, things start switching around. It's just something to keep in mind and watch for, especially on water changes. At work, the little tank on my desk runs around 100% gas saturation, the tap water comes in at 108-111% saturation, which could wipe out my small tank unless I degas is somewhere.

One of the good ways to keep this a non issue is to have a de-aeration tower.
http://www.aquaticeco.com/subcategories ... ng-Columns
The nice thing about these, is that while they are made to degas to close to atmospheric pressure, they also help keep the oxygen balance in the tank good.


Integrating as much filtration into your sump, and making it easy to get to will help greatly. Separate the filtration so your bio can be left undisturbed, your mechanical is only mechanical (filter socks/bags changed every couple days and cleaned) and you have the ability to add/remove chemical filtration if needed. This is another spot where going overkill doesn't really ever hurt.

[chris brown]

hi uvvis
(Q)You aren't planning for your tank to be outside are you?
(A)no it will be an inside tank well in the downstairs of my house which is a workshop and garage still would get pretty cold down there tho. To keep my 700l tank at 29ish degrees i am running 2 300 watt heaters and even then they are struggling over winter and that's in my lounge (no insulation around the tank).


Even with good insulation surely 1 500 watt wont keep it at 29ish
I think i will start with the 1 500 watt and if it don't work just keep adding more
(it seems you no what you are talking about so you will probably be correct)
i will have to start building and let you no as how i get on
first things first beta clear the space where it will go

[chefkeith]

So you are going from a 680 Liter Tank (180 gallon) to a 12,250 Liter Indoor Pond (3,236 gallons). That's a bit of a jump.

For every big plan like this, you need to have big back-up plans also. IMO, you'd be better off building two large tanks, instead of one. Everyone I know that has built small or large tanks, including myself, has had to do maintenance or repairs about every 1-4 years, when they'll need to shutdown and completely empty the tank. When worse came to worse, some people would end up moving their fish into kiddy pools during that down time. So think more about practicality, back-up plans, power outages, quarantine tanks, and the longevity of the tank, fish, and yourself.

As for heating, a tank that size is going to emit enough heat to heat the entire room. You'll probably have to insulate the entire basement or build a well insulated fishroom in the basement.

[chris brown]

Yea it is a big step but i will take my time and do it correct.
As for the back up plan i wont be adding any tropical fish into it for at lest a year after it gets filled i will just have some goldfish in there to cycle it and if anything happens they can just go back into the pond easily. when the tropical fish go in i will keep the 700L for backup (along with 3 200L)and in the build i will make a half wall so when fully drained for maintenance etc the fish can all be put into the other side of the wall which will keep water

and yes i will be insulating the hole down steers as sum stage it will be a spare room or kids room

[David R]

Sounds like a good project, looking forward to seeing how it progresses!

I did a 'behind the scenes' tour of the Napier Aquarium last year and had a good look at how they filter all their big tanks. For the mid-sized ones (similar to yours, roughly, not the huge shark tank!) they had a large plastic sump, the water flowing from the tank went through a couple of filter socks (http://www.particlesolutionz.co.nz I am also running them on my 1400L tank) and once in the sump was pumped up to a big TMC bio tower, and then pumped back to the tank. The TMC towers are great, but so expensive by the time you get them here its not worth it, you could easily DIY something thats nearly as good for a fraction of the cost.

I would suggest you read thru 'johnptc' on monsterfishkeepers posts about building and extending his mega tanks (here). I'd seriously look into concrete blocks (or even poured concrete) for a tank of this size, the only down side being the poor insulation properties of the concrete. This could possibly be overcome by heating the room with a heatpump to around 26-28C to reduce the difference in temp between the air and the water, it would also mean you could get by with less heating on a day-to-day basis, but with a couple of others as back ups set a couple of degrees lower for bringing it back up to temp after water changes or in case the primary heater fails.

I guess the shape is due to the shape of your basement? A longer more riverine tank would be better suited to the loaches, but having 3.5M to swim in any direction will still be great! How are you planning to access the tank? will you be getting into it if need be? Are you able to walk around all sides?

[chris brown]

I guess the shape is due to the shape of your basement? A longer more riverine tank would be better suited to the loaches, but having 3.5M to swim in any direction will still be great! How are you planning to access the tank? will you be getting into it if need be? Are you able to walk around all sides?[/quote]
i have had a look at monsterfish builds they were very helpful i think ill be building it out off wood with metal bracing in the corners and across the middle

yes the shape is because of the shape of the basement
and yes i will be getting into it if need be i will be making an access door coming in from the next room (back corner of the tank)
there will be one window on the front and you can walk around half of it, i will upload some pics of were it is going soon.