Thread: Fish tank stand build.. Advice please.

Gee - if I were you there's only 700 kilos of weight in that water, so I'd half lap the top rails & cross members into your 4 x 4 hardwood legs, and house the lower rails into the legs also. (This way you don't need 8 inch, 12 gauge wood screws).
I'd use epoxy resin (Araldite 72 hour / 3 day cure).
I'd also drill thru the joints and use bolts with washers to hold it all together rather than screws. (and youd only need 5 inch x 1/2 inch bolts).
Others mileage may vary!
Be sure and put some high density polystyrene foam sheet/s under the glass tank / on top of the timber frame to absorb any irregularities, in the degree of flatness of the top of the frame so that the weight of water doesn't crack the bottom sheet of plate glass of the tank.

If it were me I'd weld up the frame out of steel in preference and put some slight splay on the legs for extra balance to help prevent overbalancing of the tank in say an earth tremor or quake for e.g.

When that much water is in an un-baffled tank and there's any movement (like on a ship for example) the sloshing around of the water is called "free surface effect" and it can start tanks toppling of they aren't well balanced. In boats (with metacentric heighs and GZ righting curves) free surface effect has been known to capsize a vessel before today...

You don't want 700 kilos of water and glass "capsizing" with its stand, in a room that should never move - the blokes who built the "Gnu Cue Lar" reactor at Fukushima didn't think you needed to allow for earth tremors & subsequent tsunamis - and look where Japan is now - best to plan for the best and prepare for the worst.

Others may have better suggestions.

Oh and don't put that stand and tank on a timber floor unless you strengthen it underneath first with extra stumps/pillars/bearers & joists to carry the excess loading of all that water in small localized area that the floor as never engineered to cope with. Not a worry if your built on a concrete slab.

Cheers!

Thankyou so much for your reply.
Made more sense then what the other forum was telling me!
I'm on the second floor of an apartment building and the flooring is like solid re enforced concrete.. No problems there! haha.
the stand itself over all height is default at 30 Inch tall which mind you is shorter then my current 3fter.
The structural frame would be completely 4x4 wood top brace legs base support etc.

I understand that metal maybe a better and probably lighter option I'll take a look into that.
It's really hard to explain what the frame would look like but I think maybe this may help a little....
Build Your Own 187.5 Gal Aquarium Stand

That is my blueprint so to speak. I'm no good at drawing! so that site helped me a tonne!

Thanks again.

Agree with most of Timeless's advice.

I owned a pet store for almost 20 years so have "a bit" of experience with stands. Timber is fine for stands, even large tanks, as long as the joints are solid and it's well made. Bolts are definitely the way to go, and there is no such thing as a stand that is to strong. Styro is mandatory between the tank and the stand.

As far as being concerned about earthquakes, lets face it, in Oz, I would be more concerned about crossing the road and being run over, or even winning the lottery.

On the plans it doesn't show a top for the base!!!!! I would recess a top in your base a minimum of 19mm.
Kryn

Agree with all the advice above, I have built a 4 foot tank so similar in design so yours should work well. I used liquid nails and nails I had a 19mm MDF top and a sheet of 12mm polystyrene foam between the top and the tank. I didn't worry about the tank toppling over( it never did) it was on a carpeted timber floor.
cheers

All of you have given me great advice.
The top of the stand will be tabletoped. With polystyrene!
I will take note of the recess of 19mm is that for more support?
LOL at

As far as being concerned about earthquakes, lets face it, in Oz, I would be more concerned about crossing the road and being run over, or even winning the lottery

You have 2 dangers to contend with.

1. Multi - story.

This means a suspended slab concrete floor. It SHOULD be OK, (If the slab was poured right with the reo mesh closer to the bottom of the slab than the top (i.e. in tension and not in compression when suspended).

Remember your adding a localized heavy weight over a small area... who knows what the floor was engineered for or how it was constructed.

2. Free surface effect (water sloshing side to side) is amplified in a multi story - because even small movements increase exponentially as you ascend in a building.

When you make a stand - with legs directly below (and no splay outwards) they will support gravity pushing down with the weight of water, but the balance point is easily toppled with relatively little effort from "free surface effect" of the sloshing water in an un-baffled tank.

Water is a damn heavy commodity (just pay someone freight costs to cart it in bulk for you)!

When free surface effect operates (sloshing) its like trying to stop a train in a hurry, its never going to happen.

Even a slight splay of an inch or more outwards will improve stability vastly.

You may never need it - but the day you do you'll be glad you did.

I live in Perth - I've experienced an earth tremor in my life time (Meckering).

Splay the legs - I wasn't kidding.

As a trained qualified master 5 skipper, I know the dangers of free surface effect in un-baffled tanks, and their effect on stability... I wasn't kidding, please don't listen to those who mean well, but don't know dick about the topic.

A little splay on the legs is an easy thing and adds hugely to stability.

Just coz others don't do it, doesn't mean it shouldn't be done.

My last word on it.

Originally Posted by Timless Timber

You have 2 dangers to contend with.

1. Multi - story.

This means a suspended slab concrete floor. It SHOULD be OK, (If the slab was poured right with the reo mesh closer to the bottom of the slab than the top (i.e. in tension and not in compression when suspended).

Remember your adding a localized heavy weight over a small area... who knows what the floor was engineered for or how it was constructed.

2. Free surface effect (water sloshing side to side) is amplified in a multi story - because even small movements increase exponentially as you ascend in a building.

As a trained qualified master 5 skipper, I know the dangers of free surface effect in un-baffled tanks, and their effect on stability... I wasn't kidding, please don't listen to those who mean well, but don't know dick about the topic.

A little splay on the legs is an easy thing and adds hugely to stability.

Just coz others don't do it, doesn't mean it shouldn't be done.

I agree that people should be concerned and take all reasonable precautions when ever possible. However, its possible to be overly cautious. I admit I know diddly squat, and probably even less about "the free surface effect" but having sold literally thousands and thousands of tanks, and having regularly spoken to suppliers and tank makers, I do know a little about fish tanks. I certainly don't intend to get into a 'pissing contest' over this but in my almost twenty years experience in the industry, I have never head of earthquakes being a tank issue (on the east cost of Oz.) Newcastle being the exception about 25 years ago. Even then, tanks would have been the least of peoples concerns as the damage was devastating.

As far as the slab is concerned, you are 100% correct, but in my case, I would be more concerned about the possibility of being run over by a tram when I visit Melbourne. Those things are crazy!

(My last post on this topic as well.)

Not being too much of a downer, but if there is an earthquake strong enough to knock over a 700kg fish tank standing on 90x90 legs, I'd think the fish would be the very least of your concerns.

All good advice as above though.

I thoroughly agree with the styro and MDF underneath. My family had a fish tank crack mysteriously after years of operation. I'd think it was the styro compressing. Perhaps to replace it every year or two. The MDF is very good advice...I did just this under a bench I use both a drill press and bandsaw on. The extra sheet of 19mm MDF has done absolute wonders for stability, tension and rigidity.

Hi,
I was not going to post in this thread but from my experience in building a few tank stands ,I have to contradict a couple of points. I have never filled in the top and the stands I have seen for sale have not been filled in and you defiantly don't want to use MDF anywhere near that much water. I use a full size piece of poly styrene to insulate the bottom. The poly not only helps with irregularities but protects against disasters like a grain of sand cracking the tank as it just sinks in instead of trying to support the whole tank on it's point.
Just for the Forum law that it didn't happen if there is no picture, here's one I prepared earlier. IMG_0007.jpg
Have fun
Regards

A 700 lt tank would weigh approx 700kg for the water, but you have to add the tank weight, gravel, rocks and the weight of the stand ect. I don't think you would get much less than 900-1000Kg weight in total. Also being 30" high, your glass probably is 12mm thick so it will be heavier than a 2.25' or 2' tank

I built all my aquarium stands out of steel, and never had a problem with with any of them, I don't splay the legs on any of them. Having said that I am a competant welder but don't know what your welding/designing skills are like, however any stand whether built out of steel or wood will fail if not built right, and 700lt of water is not what you would want to come smashing down.

Unless you are on a concrete slab on the ground level, you would be advised to take into consideration the load bearing points in your floor, just because you have a concrete floor (but are not on the ground floor) doesn't mean that the building was designed to take that weight in a very narrow section next to a wall or something. Just my 2 cents worth, hope it helps.

Cheers

Ed.

Nothing like resurrecting a 6 year old thread...

Originally Posted by elanjacobs

Nothing like resurrecting a 6 year old thread...

and wheres Manchester?

I think a lot of us are guilty of replying to posts without checking the original date of posting. Be nice .. new member to our forum and could be new to forums in general.