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how big is too big?

11K views 25 replies 15 participants last post by  BryceM  
#1 ·
I'm starting to think about my new aquarium that I'll be getting in May/June of next year (graduation present) and my question is, as the title says, how big is too big? I was looking at maybe a 125, but then the 180 looks really nice too, and then there's the 225 that's the same length, just a bit taller... When does it get too big that maintainence takes an entire day or you have enough clippings to fill a small tank each week? My work schedule will be 3-4 12 hour days a week, so some days I won't have time for anything, other days I'll have time... How much does the electricity on a tank that size run a month too? Would getting the 225 just be asking for trouble? The largest I've had to date is a 54g, that's really my moms, so it's really just my 29g...
 
#2 ·
I recently set up a 180g tank. I love the size & shape of it because it allows for tons of options when it comes to aquascaping. I will strongly caution you though, that expenses scale up VERY quickly with big tanks. Also, you really need to pay attention to floor strength, circuit availability, and your ability to reach into the thing to take care of it.

I set mine up so that water changes are simple - just open & close a couple of valves. A 50% WC takes about 20 minutes. Smaller tanks allow you to get away with a Python or a siphon, but you'll quickly tire of maintainence if it takes too long. Neglect the tank and you'll soon have an ugly mess of truly massive proportions.

You'll need a good plan for effective lighting, a source of ferts (try buying Excel for a 180g tank), a way to distribute CO2 evenly to the whole tank, and I'd recommend a very well thought-out plan to avoid too much start-up algae. Ask me how I know.

As far as power consumption, my tank uses:
closed-loop pump & Eheim canisters ~100 W x 24 hr/day
lights ~600W x 10 hr/day
heaters ~600 W x 1 hr/day

total = 9,000 watt/hr/day = 9 kWH/day * %0.06 = $0.54/day = $200/year

My power is cheap though, only $0.06/kWH. California rates will be much higher.

Big tanks are fun, but you need to do it right the first time. Extra planning & effort up front will save tons of headaches down the road.
 
#3 ·
Hi Cassie. I hope you're doing better!

Regardless of your dosing methodology, you'll likely want to do 25%-50% waterchanges weekly. That could be arduous, cost notwithstanding.

That's one of the reasons I decided to go really nice (ADA) instead of really large.
 
#4 ·
My tank is 48x24x24. Odd size for a 125. After I got it, wasn't sure if I really liked the idea of a taller/wider tank, rather than the longer (6 foot) 125 gal's. Once settled in though, I realized that most lighting fixtures were 4-foot wide, and being 2 foot wide put my mind at ease for having a permanent home for my BGK. It also allows to grow plants pretty tall.

Cons: I had to buy a household step-stool to be able to plant the back of the tank. Even at that, it's still somewhat difficult to reach the back center. It weighs alot, I estimate at 1500lbs. The tank alone, empty, weighed prob 250 lbs.
 
#5 ·
in my opinion, above 300 gallon is where conventional equipments reach their limit. Height makes things difficult in a planted tank, i would not go above 20" max. Width and depth are what's important.

So in your case, i would pick the biggest tank below 300ish gallon that has the most width + depth and a height of 20".

With such a big tank, it will be very nice to see it fully planted with some REAL fish. Instead of just a few small schools of rasboras/neons..boring! :)
 
#6 ·
thanks for the responses...yes, John, I'm feeling better, just a bit of a cough left over. I know I need to have everything planned out, that's why I am starting now! I definantly plan on it being high tech with high lights, pressurized co2, and probably dry ferts a la Greg Watson.

Guaiac, can you explain your set up for water changes? I was thinking of possibly going with a continuious water change set-up, but I'm not sure how much I'll be able to do that, with living in an apartment. As for structural/curcuit stuff, that's stuff I plan on going in asking when I start looking for an apartment.

In regards to evenly distributing CO2 throughout the tank, would you recommend actually getting two systems and having one on each side, vs just putting the diffuser in the middle of the tank?

as for the weight of the tank (empty, I know when it's full it'll be irrelevant), I was thinking about possibly going with acrylic. Any comments/suggestions on that? I know it scratches easily, but it'll also be easier to move in...
 
#13 ·
Guaiac, can you explain your set up for water changes? I was thinking of possibly going with a continuious water change set-up, but I'm not sure how much I'll be able to do that, with living in an apartment. As for structural/curcuit stuff, that's stuff I plan on going in asking when I start looking for an apartment.

In regards to evenly distributing CO2 throughout the tank, would you recommend actually getting two systems and having one on each side, vs just putting the diffuser in the middle of the tank?

as for the weight of the tank (empty, I know when it's full it'll be irrelevant), I was thinking about possibly going with acrylic. Any comments/suggestions on that? I know it scratches easily, but it'll also be easier to move in...
Cassie,

You can see what I did for my 180g in this journal.

As far as acrylic goes - if you want to have this tank for a long time I'd recommend glass. It costs more and is heavier, but the eventual scratches of acrylic really look bad after a while. Also, on a big tank, it's hard enough to reach inside a glass tank. The cutouts on an acrylic tank are even smaller, making it harder to reach the back corners.

If you think there is a possibility you'll be moving in the next 5 years I'd avoid anything larger than a 120 or 125 like the plague. DO NOT underestimate the work & planning necessary for a big tank. Done correctly it can be a blast. Done poorly, you'll burn out on the hobby very quickly.
 
#7 ·
If you go with a large tank, anything over 125 gallons you should really look at the over all weight. At a little over 8 lbs per gallon, a 300 gal tank will weigh over 2500 lbs with stand and all.

I happen to be a floor joist engineer...... If your joists are running perpindicular to the tank, better, if they are running parallel, you could be in for trouble. If the tank is in the middle of a room you could bend the joist badly. if the tank is near a wall you could shear off a joist or two (or three!) worse case scenario is in a corner where the tank sits mostly on 1 or two joists, it will bend it and break it off at the end.

Most floors are designed to carry 40lbs psf live load, this is to say, load that is dynamic, it comes and goes. Fish tank weight stays, it is a dead load and it greatly exceeds the normal 10 to 15 lbs psf of dead weight that is assumed in most floor joist designs.

Don't get too excited, hot tubs go in a lot, and they weigh a lot too, but if you do the math you will notice by the time you figure in the foot print of the tub and the weight of the water, the hot tub usually weighs in around 40 to 50 lbs psf. And, the weight is usually live, meaning the tub is drained and stands empty a lot. When we designs floors with hot tubs, we consider the loads and design the floor accordingly. People who throw in hot tubs later, get what they get. problems don't happen that much.

Another thing with fish tanks, they are near water. better stated, the floor is near water. Everytime you drop a few gallons of water you soak your floor sheathing, and perhaps the floor joists. This can drastically reduce the load carrying capacity. You come home one night to find 20 gallons of water has siphoned off the tank and you worry about the carpet........ could be the least of your worries. Hopefully you are not renting, with renters below?

I would get some feed back from a structural engineer if you are considering a 300 gallon tank on a residential floor joist system. There are things you can do to beef up the floor, things to help spread the load around. Mostly, help pick a good place outright and avoid putting it in the weekest place right off the start.

Concrete basement floor? forget everything I just said.

If you happen to have a set a plans, or the ability to accurately describe the floor system, I might be able to help avoid a major problem.
 
#14 ·
If you go with a large tank, anything over 125 gallons you should really look at the over all weight. At a little over 8 lbs per gallon, a 300 gal tank will weigh over 2500 lbs with stand and all.

I happen to be a floor joist engineer...... If your joists are running perpindicular to the tank, better, if they are running parallel, you could be in for trouble. If the tank is in the middle of a room you could bend the joist badly. if the tank is near a wall you could shear off a joist or two (or three!) worse case scenario is in a corner where the tank sits mostly on 1 or two joists, it will bend it and break it off at the end.

Most floors are designed to carry 40lbs psf live load, this is to say, load that is dynamic, it comes and goes. Fish tank weight stays, it is a dead load and it greatly exceeds the normal 10 to 15 lbs psf of dead weight that is assumed in most floor joist designs.

Don't get too excited, hot tubs go in a lot, and they weigh a lot too, but if you do the math you will notice by the time you figure in the foot print of the tub and the weight of the water, the hot tub usually weighs in around 40 to 50 lbs psf. And, the weight is usually live, meaning the tub is drained and stands empty a lot. When we designs floors with hot tubs, we consider the loads and design the floor accordingly. People who throw in hot tubs later, get what they get. problems don't happen that much.

Another thing with fish tanks, they are near water. better stated, the floor is near water. Everytime you drop a few gallons of water you soak your floor sheathing, and perhaps the floor joists. This can drastically reduce the load carrying capacity. You come home one night to find 20 gallons of water has siphoned off the tank and you worry about the carpet........ could be the least of your worries. Hopefully you are not renting, with renters below?

I would get some feed back from a structural engineer if you are considering a 300 gallon tank on a residential floor joist system. There are things you can do to beef up the floor, things to help spread the load around. Mostly, help pick a good place outright and avoid putting it in the weekest place right off the start.

Concrete basement floor? forget everything I just said.

If you happen to have a set a plans, or the ability to accurately describe the floor system, I might be able to help avoid a major problem.
david, thanks for the very informative post. I am always curious though, would a modern high rise condo able to withstand the 300 gallon weight? i am talking about 40-50 floor condos that are constructed using concret or whatever it is they use nowdays.

for example: http://www.poggenpohl.de/ENG/others/downl_shimao_01.jpg
 
#8 ·
wow, thanks for that advice! I don't think I'll likely go over a 180g tank, 225 max but most likely I'll go with the 125 or 180, and yeah, I know that full, they way about 2100lb or so. I actually will be living in an apartment, a downstairs apartment for sure, but an apartment nonetheless, and I'll be asking all the questions when looking for and selectng a place, and of course, I'll be getting insurance!
 
#9 ·
Also think about how long you intend to stay in your apartment. I haven't lived in an apartment in a long time but I remember that I never thought of it as a long term arrangement. Moving a very large aquarium, especially once it is populated with all of those fish and plants that you have spent so much time and money on, would be a real bear and even more challenging if there is any distance involved. Just a thought.
Beasts
 
#10 ·
Way back when I was living in apartments, I had a very rough time convincing landlords that even a 40 gallon tank wasn't a disaster in waiting. I can guarantee that no landlord renting an apartment above the ground floor would even consider renting to you if you mention a 200 gallon tank. And, that is a good landlord decision. The consequences of all of that weight and the possibility of dumping that much water on the floor mean it can't be done on upper floors. Now, a ground floor or basement floor, made of concrete, is another matter entirely.

Before even attempting a 100 gallon or more tank I would make sure I could install at least a semi-automatic water change system, so no buckets or hoses were involved in changing water. And, don't forget, whereever a 100 gallon or bigger tank is first placed is most likely exactly where it will remain. You cannot move such a tank by yourself, and shouldn't even think of it unless you remove all of the contents first. Smaller tanks are not much of a problem to move a bit to level them, get them closer to or farther from the wall. Then, there is the tank stand. Those get very heavy very fast too, when you go above 100 gallons or so. You again need to put it in exactly the right location the first time - or have several big friends to help on a moments notice.

But, I really loved my 120 gallon tank when I had it. There is great satisfaction to using that size tank - you can almost always add more fish if you like, your plant choices are almost unlimited, and they are very impressive.
 
#11 ·
as I said above, it will definitely be a bottom level apartment, and I'm likely going to be there for a while. It'll be a LONG TIME before I'll be able to afford a house here in SoCal, if ever, and I don't have plans to leave the area, so my intention is to pick an apartment with long-term in mind.

I should probably read up on auto or semi-auto water changes, to see how easy/hard that will be to set up. This is exactly why I'm asking these questions now...since I have nearly a full year to figure things out and decide on what I really want and what is actually practical
 
#12 ·
Not sure how old your apartment complex will be but make sure the electrical system can handle all that equipment. My apartment building still uses those old "screw-in" fuses. When I get my 40g set up I have to take down at least two tanks because if I don't I may just have way too much going through a tiny fuse (10A I think).
 
#15 ·
One thing that people often forget to take into account (or severely underestimate) with large planted tanks is the amount of plants they will need and the associated cost.

I've seen large high light high tech setups where everything was planned out very well and then when they saw what they would need to spend on getting a healthy plant mass into the tank they decided to start off with fewer plants. These tanks usually end up as large algae show tanks and a lot of work and time is required to get them right again.

So remember: large planted tanks = large amounts of $$$ on plants is a must! ;)
 
#16 ·
Newguy,

Generally, floor systems are designed to handle 40 live and 15 dead psf regardless of construction method. Concrete can certainly handle more weight in most cases, but that doesn't mean they build it to handle more weight. Also, look out for concrete floor coverings over wood floor joists. If the floor has extra capacity, you wouldn't know it without getting a structural engineer to run some calc's.

To give an idea of how close the floor can be constructed to max, people will often add a gypcrete floor covering of 1-1/2" over an existing wood floor joist system, and this weight alone fails the joists. We are talking about (only) 18 psf more. Usually the joists deflects and the concrete cracks, no biggie. A big tank will not just deflect too much, it is likely to shear off on an end if a single joist or two are carrying all the weight. Catastrophic failure.

I can't understate the impact that water can have. Any moisture will deteriorate the subfloor sheeting and eventually the joist. I would be like getting a flat tire. Image a 300 gallon tank suddenly dropping 4" on one side?

A 300 gallon tank *is* a big deal no matter what
125 gallons and up can be a big deal in the wrong spot. Definitely run the tank perpidicular to the joist. Consider adding a sheet of 1-1/8" Plywood that is 1' to 2' larger than the tank stand foot print to spread some load. Getting under the floor and adding blocking can help. a few beams and posts if in a crawl space with concrete footings would be the way to go if given the chance.

Right now my 125 gallon tank is sitting on joists perpindicular and the water damage has squashed the floor sheeting. Fortunately the floor joists are rough sawn 4x12's at 12" oc. It is an old office building converted to living. My joists are strong but the floor sheathing pretty much gave it up. My tank sags 1/2" on one side. This is due to water damage.
 
#17 ·
size and weight among all things considered.. if you venture into the 150 gal+ range..

keep in mind, you're basically stacking a full size car on a space half or 1/4 as large..

your concrete slab garage floor may not even be designed to carry a static weight of that proportions.. and even with concrete slab.. it can and will settle into the ground causing your tank to go off balance..

you will want to check with your apartment for sure, afaik, most landlords/owners will not allow a tank larger than 50 gal, and i know my landlord balked when i asked if there was a pet deposit required for aquariums, her next immediate and worried questions was "how big of an aquarium exactly are you trying to put in the apartment?"

what is also important to consider, is what is the largest realistic size you can afford the time and money to stock and maintain..

remember that not only does the price tend to skyrocket in terms of lighting, filters, stand and tank.. but the amount of substrate, plants, and fish/animal stock needed to sufficiently stock a tank of that size is significantly larger as well..

and what i think is always a big one for me..

are you sure you can access and get into all the corners of the tank without having to put on a bathing suit and a facemask+snorkel..

those big tanks tend to get tall, and deep(width) and make it hard for people who aren't 6'5" with long arms to reach the inside of the tank without serious assistance.. especially on a display stand..
 
#18 ·
ya my apartment said nothing over 100gal...mine is 120gal...opps. I am on the second floor and have had the tank there since march. It sags a bit (half an inch maybe) from the front to the back. I have it against a way but no idea if its parallel or adjacent to the joists. It hasn't fallen through the floor yet so i guess thats a good sign
 
#19 ·
oblongshrimp...

I would look into this....seriously... if (?) you are on top of one joist running parallel and the tank is falling backwards, it will deflect the joist down *and* sideways.

Lots of questions? are you next to an interior wall or an exterior wall? Typically joists run the short way, so if you are on a long wall, good chance the joists are parallel. If on a short wall, not so good chance. Are you in acorner or in the middle of room.

The worst case scenario would be the middle of a wall with joists parallel. I just ran some calc's on a 20' joist of medium grade, with a fish tank in the middle averaging 192lb plf over 5', and this produces a moment Ft/lbs of nearly 7000 lbs. More than the 1100 lbs you might figure the tank/stand weighs. Easy way to understand this is to think of it as leverage. 2 joists carrying the load cuts this in half, but still... sounds like you are slipping off the back of one joist.

Apartments are notorius for building to absolute minimum code - I would seriously look into your situation. The thing is, if the tank crumples the sheathing/joist and even if the joist bends but doesn't break, the tank is going to slip, fall or move, what 2, 3 or 6" down and or sideways. Water is going to get everywhere. My tank sags 1/2" but I *know* I am perpindicular and that the joists are OK.

You don't. you should find out. Urgent? might last a long time as is, then again you could wake up tonight with a problem.

DA
 
#20 ·
oblongshrimp...

I would look into this....seriously... if (?) you are on top of one joist running parallel and the tank is falling backwards, it will deflect the joist down *and* sideways.

Lots of questions? are you next to an interior wall or an exterior wall? Typically joists run the short way, so if you are on a long wall, good chance the joists are parallel. If on a short wall, not so good chance. Are you in acorner or in the middle of room.

The worst case scenario would be the middle of a wall with joists parallel. I just ran some calc's on a 20' joist of medium grade, with a fish tank in the middle averaging 192lb plf over 5', and this produces a moment Ft/lbs of nearly 7000 lbs. More than the 1100 lbs you might figure the tank/stand weighs. Easy way to understand this is to think of it as leverage. 2 joists carrying the load cuts this in half, but still... sounds like you are slipping off the back of one joist.

Apartments are notorius for building to absolute minimum code - I would seriously look into your situation. The thing is, if the tank crumples the sheathing/joist and even if the joist bends but doesn't break, the tank is going to slip, fall or move, what 2, 3 or 6" down and or sideways. Water is going to get everywhere. My tank sags 1/2" but I *know* I am perpindicular and that the joists are OK.

You don't. you should find out. Urgent? might last a long time as is, then again you could wake up tonight with a problem.

DA
It's funny, I'm not into math by any means but for some reason I found everything you wrote extremely interesting. I think everyone has learned alot from these posts.
 
#21 ·
Cassie,

The only thing I would like to add to this discussion and point out to you is that since you'll be living in an apartment I presume you don't plan to stay there for the rest of your life. If such is the case, please bear in mind that sooner or later you're going to have to move your aquarium and take it with you when you go. This is always a hassle since glass does not like be move around, but if you're young and might have to move several times, this could also get very expensive if something cracks or breaks.

I'm not trying to diminish your enthusiasm (I want a big tank too), but the logisitics a large aquarium involves are something well worth noting - especially in an apartment.

As a side not, a good friend of mine was a reef aquarium maniac while in college. In fact, he had a 110 reef tank in an upstairs aparment - I know because I helped move it! (And never again!!!) Apparently his complex was over-engineered and could take the weight of it. Your milage may vary.

Jason
 
#22 ·
I'm still undecided about what I'm going to get, which depends on where I'll be living. I have recently thought about buying a condo or townhome (there's no way I'll be able to afford a house here in southern california!) instead of renting an apartment, not just for the sake of a tank, but for investment purposes as well. I saw a 160 SunSun tank that I fell in love with at the lfs. It wasn't super tall, but the depth (front to back) at least 2 feet, and it has the rounded front corners. I also really liked a 90g open top tank, so untill I get settled, I might just go with that, as it's much less complicated, wherever I live. Plus that will give me practice with a larger tank so I can see what kind of time, money, etc is involved...

This discussion has been great! It's help not only me, but a bunch of others, so, by all means, keep going! ;)