The Planted Tank Forum banner

1 - 20 of 29 Posts

·
Registered
Joined
·
527 Posts
Discussion Starter · #1 ·
Just received a Clear-For-Life 50g acrylic aquarium along with a Clear-For-Life "Laguna Pine" stand. It did not come with a mat. I don't think I need a mat. The top of the stand is one big piece of flat well-finished plywood.

Reading online, the reasons for a mat seem partly myth. For example I see people claiming it will "level the aquarium", which it cannot possibly do. However out of level a stand is, that is how out of level a tank sitting on top of the stand will be, mat or not. In fact a softer mat may make an out of level tank worse by compressing more on the lower side thus making the aquarium even more out of level than the stand. The other reason sited for a mat is to "smooth out the surface". Now that could make sense if I was maybe putting this on an unfinished surface or something with exposed screw heads, nail divots, etc... which I am not. On the flip side, I imagine if putting large stones and/or heavy decor in the aquarium (which I will be), the load on the floor of the aquarium could be a little uneven. If it's on a mat, I think that could cause some local slight sagging under heavy objects versus if it is sitting on a flat hard plywood surface.

In my situation I cannot fathom a reason why I'd want to put a mat under this, it seems like it would cause more harm then good. Does it make sense to go without a mat?
 

·
Registered
Joined
·
622 Posts
The issue is that nothing is perfectly flat, which is what the mat will make up for.
Short of machining flat a strong metal surface for the stand. Wood will always have tiny imperfections along the top of the stand, and this will show itself more if it were to get wet and warp.

It's more of a preventative measure than anything. If you don't care about a possibility of your tank cracking a panel randomly, then go without the mat and hope for the best.
 

·
Registered
Joined
·
527 Posts
Discussion Starter · #3 ·
If wood were to warp, a neoprene mat would follow the warp. Also a mat will have tiny imperfections as well.

Has anyone out there ever had an acrylic tank on a quality solid piece wood stand and had it "crack randomly"?
 

·
Registered
Joined
·
622 Posts
If wood were to warp, a neoprene mat would follow the warp. Also a mat will have tiny imperfections as well.

Has anyone out there ever had an acrylic tank on a quality solid piece wood stand and had it "crack randomly"?
The mat works so that when pressure is evenly applied through the pane on the bottom of the tank, the mat will even out and fill in all the tiny imperfections in the surface of the wood.
if the wood warps while under a mat, the mat will compress and prevent the pane from new pressure points.

Like I said before, it's a preventative measure. Buying a mat for less than $20 is a lot less than possibly thousands of dollars in repairs if 50 gallons of water were to empty out of the tank.
 

·
Registered
Joined
·
1,102 Posts
I have a 5 foot long 75 gallon acrylic tank and I sat it on 1/2 inch foam board . The foam will smooth out bumps in the wood and keep the tank on a solid surface . Look up a King Of DIY video on a tank busting from a screw head on the stand top . I know it is a glass tank he is talking about , but the principle is the same I think .
 
  • Like
Reactions: ChuckM

·
Registered
Joined
·
527 Posts
Discussion Starter · #6 ·
Good points and I have had one under a 20 gallon long acrylic between it and a piece of plywood. I'm just re-thinking this and believe I'm going to try without this time. I have a nice piece of furniture that has a smooth top, no bumps or anything.

I think a mat on top of a smooth hard surface actually makes an acrylic aquarium experience MORE stress since the mat itself is not completely stable. Eventually the squishy cells collapse and the mat flattens. If that doesn't happen exactly evenly then it places stresses on the bottom of the tank in the areas where the mat has flattened more.

Also I don't know if the density of stone is more than water, but if it is higher, then placing stone in an acrylic aquarium on a base that "gives" would cause the bottom to bow slightly under the heavier than water items, thus creating stress. A flat well sanded piece of plywood would have no give and would create no stress.

It's a new trend to put these mats under there. Were there lots and lots of exploding aquariums before mats? My hypothesis is that the mat is at least partly a myth. People say if there is just a grain of sand under there it will cause a crack, but ya know, just clean under there before you put the aquarium on it!

I guess I'll be the guinea pig and try the mat-less aquarium. I'm also going to call Clear-For-Life tomorrow to see what they say. They did not send it with mat and I purchase a full aquarium + stand set. My bet is they say no mat. I'll report back the answer on this thread so everyone is in the know.
 

·
Registered
Joined
·
497 Posts
Mats are used for rimless glass tanks to help eliminate any pressure points applied to a small area of the glass. An extreme example would be a pebble between the glass and the stand. Without a mat it applies pressure to one very small area and crack the tank. With the mat the pebble just gets pushed into the mat and the pressure point is eliminated.

Now there shouldn't be any pebbles on your stand but most people believe a stand top is never perfectly flat like the glass bottom is. I'm sure a person who does car body work could fill and block sand it flat no problem but block sanding a large area isn't the norm in woodworking. Usually a small orbital sander is all that's required to make it visually flat. This will leave high and low areas even if you don't see it. If you have a commercial top on your stand it might be pretty darn flat, can check with a straight edge. Most play it safe and use some type of mat just to be sure.

I have no experience with acrylic but don't think it would crack on a pressure point quite as easily as glass does. Can't say I've ever seen an acrylic tank on a mat personally.
 

·
Registered
Joined
·
527 Posts
Discussion Starter · #8 ·
Mats are used for rimless glass tanks to help eliminate any pressure points applied to a small area of the glass. An extreme example would be a pebble between the glass and the stand. Without a mat it applies pressure to one very small area and crack the tank. With the mat the pebble just gets pushed into the mat and the pressure point is eliminated.

Now there shouldn't be any pebbles on your stand but most people believe a stand top is never perfectly flat like the glass bottom is. I'm sure a person who does car body work could fill and block sand it flat no problem but block sanding a large area isn't the norm in woodworking. Usually a small orbital sander is all that's required to make it visually flat. This will leave high and low areas even if you don't see it. If you have a commercial top on your stand it might be pretty darn flat, can check with a straight edge. Most play it safe and use some type of mat just to be sure.

I have no experience with acrylic but don't think it would crack on a pressure point quite as easily as glass does. Can't say I've ever seen an acrylic tank on a mat personally.
Yes if i had a rimless I would definitely put a mat underneath that.

I didn't articulate my point well. My hypothesis is that since acrylic flexes, placing an acrylic aquarium on top of a flexible surface such as a neoprene mat, will allow the aquarium bottom to flex, which probably causes more stress problems than tiny micro scratches in the wood from the cabinet maker's sander. An example would be placing a heavy centerpiece rock in the middle of the aquarium. It's denser than water and so would push down on the surface of the tank bottom with more force than the surrounding water. Since the mat underneath can compress, it would allow the aquarium bottom to sink a little in the middle under the rock, which is probably something we do not want.
 

·
Registered
Joined
·
375 Posts
Surely there's only one reason for a mat beneath a tank?: to stop the glass shattering under stress if there is a slight unevenness (e.g. small bit of grit) on whatever the tank is standing on.

I have no idea of how an acrylic stand will respond in similar circumstances, but sure it would be much more forgiving than glass. But that said, what is your reason for not wanting to use a mat at all? I'm not sure even the best finished piece of plywood could be called "flat". Using a mat just seems a sensible precaution to me, even more so with a glass tank admittedly, but you've still got 200 kg of water resting on a few mm of plastic sheet and the result of a fracture... well, not good.

I think the argument about it doing more harm than good if you have uneven weight distribution (e.g. big rocks) is probably over thinking it. Slight flexing of the acrylic under a big rock etc might perhaps be beneficial as the flexing distributes the induced stresses across the sheet, rather than just at a point. But I really think that's overthinking it and these are all second or third order effects. I can't see that having a mat would have any downside to be honest.

But let us know how you get on if you decide to go the no-mat route!
 

·
Registered
Joined
·
506 Posts
The problem is at the joints of either glass or acrylic. That is where there the issue is. Since the seams of the tank will not “flex” the break I have seen glass and acrylic tanks break at seams. Any stress is bad on a aquarium. It’s your tank so do what you want just remember that you could have put a mat under your aquarium. When your tank cracks in the middle of the night.
 

·
Registered
Joined
·
527 Posts
Discussion Starter · #11 ·
I have no idea of how an acrylic stand will respond in similar circumstances, but sure it would be much more forgiving than glass. But that said, what is your reason for not wanting to use a mat at all? I'm not sure even the best finished piece of plywood could be called "flat". Using a mat just seems a sensible precaution to me, even more so with a glass tank admittedly, but you've still got 200 kg of water resting on a few mm of plastic sheet and the result of a fracture... well, not good.

I think the argument about it doing more harm than good if you have uneven weight distribution (e.g. big rocks) is probably over thinking it. Slight flexing of the acrylic under a big rock etc might perhaps be beneficial as the flexing distributes the induced stresses across the sheet, rather than just at a point. But I really think that's overthinking it and these are all second or third order effects. I can't see that having a mat would have any downside to be honest.

But let us know how you get on if you decide to go the no-mat route!
My reasons are multi-fold. I don't want to buy something unnecessary. I don't want to buy something harmful - which is a possible downside (per my concern about flexing)! And I want to think through it and see what others think. There is a lot of weak science on these threads, not that that is anyone's fault because we are mostly non-scientists and enjoying the hobby beyond pure scientific pursuit. It's important to thoughtfully and respectfully challenge notions if they don't make complete sense to us.

I contacted Advance Aqua Tanks https://advanceaquatanks.com/ who make the Clear-For-Life acrylic aquariums and stands. The customer service person recommended to NOT use a mat. He did not seem concerned about the flexing risk I asked about, although he did site that they assume a 1/2 mat compression on most mats. Perhaps they feel the flexing of the aquarium bottom does not present a problem. He said they do use mats for "very large acrylic tanks" (hundreds of gallons) but that it is "not the best idea" for smaller ones like my 50g. So officially from the manufacturer, a mat is not recommended under my acrylic tank. I'm going to follow that recommendation.
 

·
Registered
Joined
·
375 Posts
There is a lot of weak science on these threads, not that that is anyone's fault because we are mostly non-scientists and enjoying the hobby beyond pure scientific pursuit. It's important to thoughtfully and respectfully challenge notions if they don't make complete sense to us.
Completely agree, except that there isn't that much hard science "fact" about much in the hobby. Not the sort of thing any university is going to research, and too many variables anyway. But what there is is lots of experience from other hobbyists. So whilst I agree that it is important to take everything you read or someone tells you with a grain of salt, there's also a lot to be said for listening to the collective experience and wisdom! Well, sometimes anyway :grin2:

My 50 litre tank currently sits on a double layer of 1-2mm sparkly black glitter craft foam, because that's all I could access during lock down. Seems to do the job just fine, but would I get something better for a bigger tank? Yes, almost certainly! But my point being there is no need to buy a professional tank mat; craft foam, polystyrene board, old yoga mat, all do the same job. Why not go with a thin (1-2mm) foam sheet to give some 'protection' from surface irregularities, but which would not allow significant flexing of the acrylic?

I don't think anyone would do without a tank mat on a glass tank, would they? I guess your point is whether the same logic applies to acrylic tanks, right? My instinct from an engineers perspective would be yes, at least to a certain extent. You might well get away without using a mat if you have a good tank, the base on which it sits is smooth and level etc, the tank joints are all good, there are no pre-existing weaknesses or stress points in the material of gluing, it hasn't had a bump in shipping, the stars are aligned, etc, etc. If you're happy that none of those risk factors apply, then great! But I think using a mat is a sensible default position for all tanks, don't you?

I guess the only real way we are ever going to know for sure is for someone to test out not having a tank mat. If you're up for that then great, please do let us know how it goes! But I don't think I would personally be willing to risk it myself.

Let us know how you get on anyway!
Regards, James
 

·
Registered
Joined
·
527 Posts
Discussion Starter · #14 ·
Completely agree, except that there isn't that much hard science "fact" about much in the hobby. Not the sort of thing any university is going to research, and too many variables anyway. But what there is is lots of experience from other hobbyists. So whilst I agree that it is important to take everything you read or someone tells you with a grain of salt, there's also a lot to be said for listening to the collective experience and wisdom! Well, sometimes anyway :grin2:

My 50 litre tank currently sits on a double layer of 1-2mm sparkly black glitter craft foam, because that's all I could access during lock down. Seems to do the job just fine, but would I get something better for a bigger tank? Yes, almost certainly! But my point being there is no need to buy a professional tank mat; craft foam, polystyrene board, old yoga mat, all do the same job. Why not go with a thin (1-2mm) foam sheet to give some 'protection' from surface irregularities, but which would not allow significant flexing of the acrylic?

I don't think anyone would do without a tank mat on a glass tank, would they? I guess your point is whether the same logic applies to acrylic tanks, right? My instinct from an engineers perspective would be yes, at least to a certain extent. You might well get away without using a mat if you have a good tank, the base on which it sits is smooth and level etc, the tank joints are all good, there are no pre-existing weaknesses or stress points in the material of gluing, it hasn't had a bump in shipping, the stars are aligned, etc, etc. If you're happy that none of those risk factors apply, then great! But I think using a mat is a sensible default position for all tanks, don't you?

I guess the only real way we are ever going to know for sure is for someone to test out not having a tank mat. If you're up for that then great, please do let us know how it goes! But I don't think I would personally be willing to risk it myself.

Let us know how you get on anyway!
Regards, James
I don't necessarily buy that because everyone does a thing, that is evidence of collective wisdom. It could very well be that everyone is throwing their money away (I don't believe that is the case with mats, I believe they could confer benefit in some situations). The fact is nobody has done any kind of test like setup 1000 aquariums on the same flat surfaces, one with a mat and one without and see how many mysteriously explode and try to correlate that mat efficacy. I don't think such a test is possible or necessary but it does point out that there is no real evidence that mats help. People like myself have had aquariums "explode" but unless there is a known surface irregularity it is conjecture that it was related to that (probably more likely that seams gave out).

The second main premise I challenge is the notion of "surface irregularities" from which a tank needs protection. My eyes, hands, and level all say this piece of fine furniture, made by an aquarium company to fit their aquarium, is free from any irregularities. Sure there are microscopic sanding lines and grain lines, but I can't fathom how those could cause a problem. A mat would allow the bottom to flex more than some microscopic sanding line. So if bottom flex from a mat is not an issue, a microscopic sanding line sure isn't.

The notion that the tank will experience stresses if not on a mat is something I would challenge as well. A mat allows movement, it's a very small amount but more movement than a firm piece of leveled plywood. Any movement of an aquarium full of water is a stress.

Lastly I am certainly not the first person to go mat-less. The modern hobby started in the 1800's and mats are a recent development. I see plenty of people post that they do not use mats. I have no idea of what the breakdown is of mat users vs not. I'm guessing more people do not use them since the mats are kind of newer trend that has accompanied rimless and acrylic tanks.
 

·
Registered
Joined
·
79 Posts
My opinion on the mat is this: what on earth could it hurt? I see it as a extra safety against point loads that could occur from the tank to stand mating surface and from hardscape to tank interactions. All the mat really does is distribute any force concentrations on the bottom of the tank to the surrounding area of the tank by using an intermediate medium. It is the same principle as using snowshoes, or laying down and sliding on ice rather than walking. It is cheap insurance for a large purchase that can't really do any harm. You don't even have to buy the expensive mats. A used yoga mat works or some heavy felt from a fabric store would work just as well. In the end it is your tank and not mine, so you have to decide if maybe $20 is worth the potential headache of a broken tank. good luck with whatever you decide to do!

-AM
 

·
Registered
Joined
·
469 Posts
The purpose of a mat under a tank is to distribute pressure points from the stand. If you have a perfectly planer stand surface there is no need for a mat. To check to see if your stand is planer put a straight edge across diagonal corners while the stand is under an equivalent load of your filled aquarium plus make sure there are no bumps or high spots in the top surface of the stand. Pressure points are what cause problems and leaks in otherwise sound aquariums. Under load (the weight of the tank) the stand will conform to the contour of the floor it is on... for tanks of a significant size (and weight).

How do you put the stand under the load equivalent to the weight of your tank and check across the diagonals? I don't know which is why I always use a mat.

A mat will only make up for minor variations in the stand surface whether they be bumps or twisting of the top. The twisting forces are the hardest to identify and in my experience what cause tiny leaks to develop over time as the sides of the tank tries to tear the seams of the tank apart.

Is a mat required? No, definitely not. Is it good cheap insurance? In my experience it is!

I have had a 110G tall glass tank spring a very small leak that wasn't detected for several week and created a huge mess. The tank was on a cheap particleboard stand (I was in the process of building a new stand for it) and had no cushion to distribute pressure points between the stand and the tank. For $25 I will buy a foam camp pad for cheap insurance.

If you don't want to use a mat, don't use a mat. The chances are VERY HIGH that you will NEVER have a problem... if you shim the bottom corners of the stand so the top corners of the stand are planer.
 

·
Registered
Joined
·
40 Posts
For a rimless glass tank, or an acrylic tank always use a mat because the weight is distributed on the bottom, for a framed tank the weight rests on the frame (hence the stands metal, or wood without a top supporting board) and a mat would be detrimental because it pushes the glass up putting stress on the seams inside the frame which can cause the glass to fracture over time. Recently got a new 75 gallon tank and the stand was not level diagonally across, so to have a new one built according to my design I had to do a lot of learning from others who had a lot more experience at designing than I did but now this stand is built solid like a tank.
 

·
Registered
Joined
·
375 Posts
A mat allows movement, it's a very small amount but more movement than a firm piece of leveled plywood. Any movement of an aquarium full of water is a stress
Yes, a mat allows movement - that's the whole point!!! :wink2:

A small amount of movement redistributed stresses away from a point load.

The fact is nobody has done any kind of test like setup 1000 aquariums on the same flat surfaces, one with a mat and one without and see how many mysteriously explode and try to correlate that mat efficacy.
Sounds like your tank is going to be #1 of 1000 in this experiment then! We really only learn something new when someone has a hunch and does something different. The danger of course is that your tank is fine (given that you have been very careful checking the stand etc), but that someone else reads your (hopefully!) successful result as meaning "tank mats are a myth and you don't need them ever on any tank!"

Keep us posted :wink2:
 

·
Premium Member
Joined
·
12 Posts
Just received a Clear-For-Life 50g acrylic aquarium along with a Clear-For-Life "Laguna Pine" stand. It did not come with a mat. I don't think I need a mat. The top of the stand is one big piece of flat well-finished plywood.

Reading online, the reasons for a mat seem partly myth. For example I see people claiming it will "level the aquarium", which it cannot possibly do. However out of level a stand is, that is how out of level a tank sitting on top of the stand will be, mat or not. In fact a softer mat may make an out of level tank worse by compressing more on the lower side thus making the aquarium even more out of level than the stand. The other reason sited for a mat is to "smooth out the surface". Now that could make sense if I was maybe putting this on an unfinished surface or something with exposed screw heads, nail divots, etc... which I am not. On the flip side, I imagine if putting large stones and/or heavy decor in the aquarium (which I will be), the load on the floor of the aquarium could be a little uneven. If it's on a mat, I think that could cause some local slight sagging under heavy objects versus if it is sitting on a flat hard plywood surface.

In my situation I cannot fathom a reason why I'd want to put a mat under this, it seems like it would cause more harm then good. Does it make sense to go without a mat?
Did you get it new or used? I'm only asking because if used, what did the previous owner have? If purchased new I would probably follow the manufacturers recommendations as to not void any warranty.
 

·
Registered
Joined
·
527 Posts
Discussion Starter · #20 ·
I know that it distributes the force concentrations. But what point loads? If they come from the stand in the form of a screw jutting through or warping of wood, something like that would cause me to immediately abandon the stand. I'd move every thing to another tank, empty, and work through it with the manufacturer to get it replaced. Also side note, I notice my mat under my 20G acrylic does nothing to keep water off the 3/4" plywood underneath of it. In fact it may trap moisture between it and the wood. I keep it dry but water always drips down an aquarium at some point. So that is another thing that has concerned me with mats.

There are no point loads coming from the inside the aquarium if it sits on a rigid surface. If it is on a soft surface like a mat, then rocks and heavy ornaments become point loads against the bottom surface causing it to warp ever so slightly under their weight.

A glass aquarium is a rigid fragile box, especially a rimless. It seems to make sense to put that on a mat. An acrylic tank flexes like a stiff gel (they can jiggle, depending on thickness, like a very stiff cube of jello). My bet is that for stability, it is better to put such a thing on a solid non-flexible surface.
 
1 - 20 of 29 Posts
Top