Tank Leveling Gap HELP!! Please

[DN328]

Von, I cannot comment on the cement idea, but it sounds messy and may not get the function or aesthetics you are looking for (although it would be under the tank.

It's hard to tell from the picture but would it be difficult to replace the top with another say, 3/4" medium density overlay plywood? You wont be disappointed with that. Worse case some other piece that isn't warped?

 

[skjl47]

currently trying to set up a 125 gallon tank in my fish room

Hello; A rough estimate for the weight of a 125 may be as much as 1500 pounds with tank, substrate and all.

My son made the stand

hello; I understand that you want to use you son's work.

I took the longest factory cut edge I could find (the edge guard for the tank itself) and the stand itself appeared to be straight,

Hello; I read thru the posts again to see if you have responded to the suggestion of using a straight edge on the stand to check for true. Not sure if the above quote indicates that you have done so. Both the stand top and the tank bottom cannot be true or you would not have the gap seen in the photo you posted.
If the stand is true ("appeared to be straight") as you contend. The only thing I can think of now is to turn the tank upside down and lay the straight edge along the bottom of the tank itself. It follows that if the stand is straight, then the tank must not be.

Hello; have you actually removed the tank from the stand and actually used a straight edge across the top of the stand in several directions?

 

[DN328]

Hhhmmm, I thought OP confirmed the stand top surface was not flat and tank was fine. Hence, the suggestion to try to replace top of stand.

 

[skjl47]

Hhhmmm, I thought OP confirmed the stand top surface was not flat and tank was fine. Hence, the suggestion to try to replace top of stand.

Hello; For a time this was my understanding as well. The more recent post (from which I took a quote) seems to indicate that the OP is saying that the stand is straight from using the tank edge as a reference. I have been basically going by the assumption that the bottom of the tank is true. I guess it is somehow possible for the plastic base along a tank bottom to not be true even tho I have not come across such. This is why I asked again if a straight edge has actually been used.
Something is not straight. Either the tank or the stand. I thought from the photo that it must be the stand, but things in photos can be deceiving. I read thru the posts again to see if the OP had reported using a straight edge. I am still not sure.

By the way, to the OP. The edge of most long levels is usually pretty straight if you do not have an actual straight edge.

 

[vonRies]

have you actually removed the tank from the stand and actually used a straight edge across the top of the stand in several directions?

I was only able to check the top in one location, right in front of the tank. I used the factory cut edge of the cardboard edge guard that I took off of the tank lip. It was just under 6' long, as well as a 4' carpenters level.

The only thing That makes sense to me, thinking geometry here, as to how they could both be straight and still not line up is as follows. If the plane of the top and the plane of the tank are not parallel. It has been a very long time since I took trig. But if my calculations are correct it would only take a 0.2 degree angle to get a 1/4" difference over a 72" long run. even if the tank and the stand's top are on the same plane I don't claim to be able to read a bubble level (even a 4' level) that accurately. Someone please check the math. I have been out of it for way too long to remember if I did it correct or not. I could easily be wrong.

 

[skjl47]

was only able to check the top in one location, right in front of the tank

Hello; I do not understand this. My best advice has been and continues to be that the stand top needs to be checked in several places and directions. Sounds like the tank is being left on the stand and only the front edge is being checked.

factory cut edge of the cardboard edge guard that I took off of the tank lip

Hello; While a length of cardboard may be true it is not known to be true. A straight edge is known to be true (or at least very close to true). Your four foot level may have a straight enough edge. A couple of my long levels are metal and very close to true.

how they could both be straight and still not line up is as follows. If the plane of the top and the plane of the tank are not parallel.

Hello; This seems to be off in the weeds a bit. If you have only checked in one place then there must be something out of true somewhere else, which is why I have suggested you check the stand in several places and directions.

to be able to read a bubble level (even a 4' level) that accurately.

Hello; At this point the bubble in the level does not need to be read. I have been thinking the goal to be checking the stand for flatness (true). The edge of your 4ft level is what to look at to see if it lies flat along the stand top in several directions.


Hello; Other than what has been already suggested, I have no additional useful thoughts to add. A 120 gallon tank can cost in the hundreds of dollars. The damage to floors, carpet and a house from 120 gallons being spilled can be many hundreds of dollars more. A decent straight edge should not cost a great deal. Been a while since I bought one but maybe under 20 dollars?

Good luck

 

[Fish Eat Fish]

Here's a way to check the top. You must take the tank off. It isn't sitting correctly so there is no reason to leave it there anyway. If you don't have a straight edge long enough you can use string. I'd use something fairly fine but strong like chalkline string. Place on either end of the empty stand two blocks of wood or something that won't roll of known dimensions. Let's say you rip two pieces such that they are "1 tall. Then you just lay the string over these block, pull the ends until the middle is quite taught, and measure the middle and other various points to check for differences from the ends. If your stand is true every measurement will be 1". Make sure to move the blocks and check several locations as you could have a "hump" somewhere. Most importantly check along the areas where the tank frame would be resting. My suspicion is that somewhere near the middle you will find a high spot. If you don't and it is all true then...your tank is messed up in quite an unusual way. The only possibility I see then is that the frame isn't sitting flush with the glass and is warped.

It's also possible that the whole stand has a twist to it. To check for this make sure to check corner to corner.

 

[Drstrangelove]

Hello; This seems to be off in the weeds a bit. If you have only checked in one place then there must be something out of true somewhere else, which is why I have suggested you check the stand in several places and directions.

Hello; At this point the bubble in the level does not need to be read. I have been thinking the goal to be checking the stand for flatness (true). The edge of your 4ft level is what to look at to see if it lies flat along the stand top in several directions.

This is exactly right. A level isn't just to read the meter (bubble) but to also examine the spacing under the level against the object being measured. The bubble will only tell you if the ends of the level are "level"---it will tell you nothing about what is true underneath the level. However, you can use the level to show you visually if the area under the level is warped by examining any gaps between the level and the surface. (This of course assumes a metal level which is the kind most people have.)

You would want to rotate and move the level all around the surface of the table top while examining underneath the level to see if there are gaps. That will show any warping if there is any. Of course, a surface that is perfectly flat still might not be level, which is when you could also use the meter.

The same process can be used on the bottom of the tank.

One (or technically) both of them has to be warped, although my bet is on the table.

 

[vonRies]

Hello; have you actually removed the tank from the stand and actually used a straight edge across the top of the stand in several directions?

Hello; I do not understand this. My best advice has been and continues to be that the stand top needs to be checked in several places and directions. Sounds like the tank is being left on the stand and only the front edge is being checked.

You must take the tank off.

You would want to rotate and move the level all around the surface

I agree, however, here is the problem with that. I am severely handicapped and can not move it. That is why I had my adult son come over and build it instead of doing it myself. He does not live with me and lives some distance from here. I am trying to find the best possible solution, before I ask him to make another trip over here.

 

[skjl47]

I agree, however, here is the problem with that. I am severely handicapped and can not move it. That is why I had my adult son come over and build it instead of doing it myself. He does not live with me and lives some distance from here. I am trying to find the best possible solution, before I ask him to make another trip over here.

hello; Thanks for the additional information. Speaking for myself there does not seem to be any simpler way around the problem other than what has already been suggested. Perhaps others will have an idea.

If cost is not a factor then a professional carpenter can build a true stand or at least check the current one for true.

I may have missed this if you have already mentioned it, but is the tank new bought from a store? I ask thinking that perhaps the store will have a stand for the tank and may be willing to do the setup if you explain the situation.

here hoping it works out for you and again good luck.