Building my 11 000 gallon saltwater Tank - Discussion and Brainstorming

  • We are currently upgrading MFK. thanks! -neo

What do you think?

  • Sounds plausible at these costs

  • Plausible, but probably a little more expensive then anticipated

  • No way, this will cost a fortune more than anticipated


Results are only viewable after voting.

Evolutionnext

Feeder Fish
MFK Member
Jul 1, 2015
21
12
3
42
Hi there,

I am in the process of building my house (in Aastria, Europe) and being an aquarium fanatic (and a little crazy according to my frinds, parents and fiancee) I need to integrate a REALLY BIG saltwater tank into the house.

The aim is to keep saltwater life and maybe a few small sharks and corals in it. I am currently a moderately successful reef tank keeper.

Before the question comes up, I'm not poor, but I'm not rich either... so the plan is to make it with a relatively low budget and low maintainanace costs.

BTW: I would be interested in some freelancer/expert willing to help with the project for an acceptable cost...

The reason I am posting this here is because I would love some critical discussions, constructive criticism and so on... and because I would have loved to find a thread like this somewhere were it not me who built it. So here it is.

1kEGYCs.png


Its the blue thing at the top.

The dimensions are as follows:

Area: 17m² / 180 foot²
Water depth: 2.5m / 8 foot
Water Volume: 42 000 Liters / 11 000 Gallons

The glass front:
I will have 2 viewing panes. The first one will face the living room and be of the dimensions:
18 foot wide, 7 foot high and 4 inches thick
=5.5m x 2.2m x 10cm

So basically it will be an entire wall of acrylic.

W1TG0Wz.jpg


Orginally I wanted to have it twice as big, but well... costs do matter ;/

Anyways.. I went to a professional building such aquariums to ask him for a quote. The quote was (all included) €180 000 for the aquarium and equipment and so on.... which was too much for my budget.

So I realized I would have to find cheaper solutions to do this.

The curent approach will be the following:

I got a quote for the acrylic panes (there is another smaller one to the bathroom).

$21 000 for both of them including shipment from Asia to Austria. Not too bad, considering that sourcing it here from a professional would have cost me 3 times that.

By the way.. if anyone thinks, 10cm / 4inches is too thin for a water depth of 8 foot, now would be a good time to tell me! ;)

So I will have a construction company build me the tank out of concrete, with window-like openings that will fit the acrylic panes.

He0ReVW.png


YzZ7i0f.png


Building the room out of concrete is not much more expensive than building an extra room in a house... the walls are about twice as expensive, but considering that you dont need flooring, tiles and stuff, its not too expensive to get this concrete tank done.

And now this is where it starts to get a bit vague and where input from anyone would be appreciated.

From what I have read about plywood tanks, coating the concrete walls with suitable acrylic would be the way to make it suitable for keeping fish.

The first question: Can this be done DIY? Any hints, Input on what Acrylic to use and if/how the concrete would have to be treated before the acrylic is painted on? Any ideas how much acrylic is needed? Any things I am forgetting?

Ok, assuming the acrylic is on the concrete, the next step would be to put the Acrylic panes in.

The edges would be filled in with some silicone-like material. This is what I saw at a public aquarium:

16422275_10158319689340093_847479359513283081_o.jpg


The questions: Any idea what material this is? Its rubbery and quite soft to the touch. Can this be done DIY or is it tricky to do? I am still trying to figure out how to get this part done...

Well.. then the tank should be ready for water. My guess would be that I should probably flush it a few times before putting the right water in. I got an offer from a public aquarium, that I could have a truck load of saltwater from their large tanks.... so the ecosystem would set itself up faster.

The room above the tank would be essentially the same size with concrete floor, but with a hole in the center so I can jump in.

WATER EXCHANGE
I want this to be as low maintainance as possible. I am planning to put two water tanks in the cellar that would hold 15 000 l / 4000 gallons of salt water. The plan is to have a system, where exess water simply goes into the canal, so no flooding can happen (not sure about the english term.. sorry).
I would then have a small tube of continous water flow from the tanks in the cellar into the tank. I would time it so I have a 10% water change per month. This would give me a rough no-maintainance period of 5 months, before I have to refill the tanks in the cellar with fresh saltwater.
Evaporationg water will have to be replenished with osmosis water.
Questions: Any idea how I can conbine the continous refilling with saltwater form the cellar and the evaporation-replacemnt with osmosis water? Maybe replace evaporation in the day and add the salt water from the cellar in the night?
Second question: Can I use Rainwater instead of osmosis water? I could catch it in a tank and use that as source for refilling the tank.

LIGHTING:
Now thats the expensive part. My dream would be to have crals in assorted places near the surface. The idea is to have corals on rocks near the surface on either side of the acrylic pane at a depth of up to 1 meter/3 foot. That shouldnt be too hard to manage. I think moderate lighting of the whole tank would require about 6kWh to get spots of coral growth. I am looking into combining it with a solar panel system that feeds the electricity into the tank as it is produced (No loss through batteries etc.), but still this is expensive when considering a whole month of 60 kWh per day. Without Solar panels this would probably cost me €500 / $ 600 per month in electricity. My hope was to get the monthly cost to around €300 / $350.
Maybe I will skip the corals and stick to a gloomy blue Deep sea athmosphere with less light. I will have to see.

RECYCLING HEAT
The idea is to build metal casing that holds LED discs in the various colors, but which is cooled with circulating water. The hot water would then be used for heating purposes. this would at least reduce the heating cost of the house.

COOLING
Now here some input would be appreciated. A local public aquarium told me that they usually dont need to cool (in Germany).. but 2 summers ago it was very hot and they had big problems. I calculated, that with 10 000l / 2600gallons cold tap water I could cool the thing down by 5 °C. This would cost about €40/$35 per day. The idea is to have the water run through a metal tube that is in the main tank (emergency system I would just put in when needed). As an emergency system, this would probably be better than buying a several thousand $ cooling unit. Especially if it is not needed every year.

TECHNOLOGY
Now talking about the filters.... I want to keep things quite simple so I can fix and modify it when needed. I would rather not have pipes go thorugh the whole house. The idea is to get 1 to 2 of these:

aqua-medic-systemfilter-skim.jpg


Each unit costs around €15 000 / $ 16 500 and is suitable for 20 000l / 6000 Gallons of sea water.
I would start with one, then upgrade if necessary. Each unit is self contained and would be placed in the room above the water.. with simply a hose to and from the aquarium.

KEEPING THE ACRYLIC ALGAE FREE
Thats a tricky thing.... I would not want to climb into the tank 2x per week to scrape off the algae. Also an algae magnet would take ages at this size. I know an engineer who thinks he can build me an automatic scraping system that would just scrape a blade along the glass once every day. Lets see how this works... ;)

Well, thats it.

If all my plans work out, this should be an Aquarium that requires minimal maintainance:

Filling Water Tanks every 6 months
Feeding - Automated or Daily
Emergency cooling - as required every few years

Nothing else.

Now its your chance to tell me im an idiot because of getting it all wrong.... ;)

Thanks!
 
Check out NUMA's build thread. His tank is "only" 2500 gallons, but it is an absolutely beautiful cement tank.

https://www.monsterfishkeepers.com/...ncrete-mega-tank-project.438417/#post-5359149


Arapaimag's 50,000 gallon build
https://www.monsterfishkeepers.com/forums/threads/building-my-50-000-gallon-monster-mega-tank.8952/


Check out polyurea. It can be sprayed on to waterproof. It is used for water tanks, etc., for waterproofing. If I were constructing a cement tank, that is the route I would go.
http://polyurea.com/polyurea-linings/

This company has polyurea for potable water systems.
http://versaflex.com/products/
 
Nice idea and perfectly laid out question.

Sealed concrete tanks start leaking sooner or later, I was told by professionals because concrete always settles, moves and cracks. I doubt resealing would be an option but you can ask this guy too, who's done a 2500 gal tank in Switzerland 5 years ago and still going strong http://www.planetcatfish.com/forum/viewtopic.php?f=5&t=32680

I'd probably either use a rubber liner for a membrane (can be covered with concrete), 2-3 layers for safety (liner will have to be sealed to the acrylic viewing panels), or use thinner acrylic for the non-transparent walls where say 1" acrylic can rest against the concrete walls. Or FRP can be used too. It'd be important for the acrylic or the FRP to not be chemically bonded to the concrete, so they could move a bit independently of each other.

If the tank leaks a bit, however, It may be prudent to devise some kind of catching system that would collect and channel the water outside until the issues are fixed.

The black sealant is Dow 795 or its European equivalent.

If I were you, I'd probably choose a fiberglass tub with acrylic windows, a commercial product like this company makes (I have two of their 4500 gal tanks, first two links in my signature) http://www.aquaculturetanks.com/

I'd not recommend a DIY because it's a part of your house. The stakes are too high. A separate standing building or a greenhouse or shed would be a different matter. Even a basement.
 
  • Like
Reactions: PGJE
I think it'd depend on whether the buyer has to put the tank together or if it's one piece. At any rate, AFAIK they are a 100% stand up Company. They build and overbuild tanks to last.

Plus they don't and won't use glass anymore. Only acrylic for large windows. They had problems with glass years ago.

Most acrylic and glass tank makers don't provide any better warranty, usually shorter. IME.

But I hear yah. We usually get what we pay for or less, almost never more :)
 
  • Like
Reactions: Evolutionnext
Check out NUMA's build thread. His tank is "only" 2500 gallons, but it is an absolutely beautiful cement tank.

https://www.monsterfishkeepers.com/...ncrete-mega-tank-project.438417/#post-5359149


Arapaimag's 50,000 gallon build
https://www.monsterfishkeepers.com/forums/threads/building-my-50-000-gallon-monster-mega-tank.8952/


Check out polyurea. It can be sprayed on to waterproof. It is used for water tanks, etc., for waterproofing. If I were constructing a cement tank, that is the route I would go.
http://polyurea.com/polyurea-linings/

This company has polyurea for potable water systems.
http://versaflex.com/products/


Great reply.. thank you so much for the help. Especially the Polyurea... that does sound like a sensible option! I wonder if it would crack along with the concrete as it ages or if that would keep it sealed....
 
Nice idea and perfectly laid out question.

Sealed concrete tanks start leaking sooner or later, I was told by professionals because concrete always settles, moves and cracks. I doubt resealing would be an option but you can ask this guy too, who's done a 2500 gal tank in Switzerland 5 years ago and still going strong http://www.planetcatfish.com/forum/viewtopic.php?f=5&t=32680

Great info.. thx a lot.. I thought when something is made of concrete...... well.. it is set in stone... but apparently not. Ill get in touch with the swiss guy and ask him. What he did seems quite simple tough... 3 layers of sealant directly on the concrete and thats it.
But the cracking problem with concrete does worry me a bit. any idea if pulyurey coating would fix this issue or if it still is a problem afterwards?
 
The black sealant is Dow 795 or its European equivalent.

If I were you, I'd probably choose a fiberglass tub with acrylic windows, a commercial product like this company makes (I have two of their 4500 gal tanks, first two links in my signature) http://www.aquaculturetanks.com/

Thx for the description of the sealant... will check where to get this.

The dolfins guys are actually quite interesting... ill get in touch with them and see if they would be able to provide any sort of service. It would of course maybe be worth thinking about coating the walls in fiberglass to solve the cracking concrete issues... Maybe they would sell me some long distance advisory support.. ;) thx !
 
One thing I would caution you with is using some sort of machine to automatically wipe the windows. A couple things with it. Acrylic can scratch so I think you run a risk of putting a lot of scratches on your acrylic with that method. Another thing is that often those type of machines have metal parts. This is a problem in an aquarium, especially a saltwater one.

Another thing you might want to think about is the drip system. I think it could end up messing with your salinity levels, which could cause harm to corals. Not for sure on this, but it seems to me that with water evaporating and continuously being replaced by more saltwater, the salinity would end up rising.
 
  • Like
Reactions: Evolutionnext
One thing I would caution you with is using some sort of machine to automatically wipe the windows. A couple things with it. Acrylic can scratch so I think you run a risk of putting a lot of scratches on your acrylic with that method. Another thing is that often those type of machines have metal parts. This is a problem in an aquarium, especially a saltwater one.

Another thing you might want to think about is the drip system. I think it could end up messing with your salinity levels, which could cause harm to corals. Not for sure on this, but it seems to me that with water evaporating and continuously being replaced by more saltwater, the salinity would end up rising.

True on both accounts... The blade thing will have to be carfeful not to scratch the acrylic. I currently have a smaller acrylic aquarium with two blades that works like a charm. Its actually structured in such a way that only the blades touch the glass. I had problems with a conventional algae magnet with small sand grains getting stuck in between and scratching the acrylic or glass... the blade concept is better I think. What the wiper system will do is essentially simulate 30 such algae magnet blades being moved by hand.. just that its a machine doing it. A good thing about acrylic is, that you can remove scratches even on theinside with water filled in.

About the drip system... you are right.. that is a tricky thing. I guess having a water replacement system that refills with osmosis water throughout the day... followed by a 2 minute infusion with salt water at night (when not much evaporates.. at least not in the 2 minutes I pump water in) might solve the problem...
 
MonsterFishKeepers.com