Leveling 65 gallon tank and calculating saltwater needs

[jd120988]

Hey guys, ive been out of the game for about 3 years and I've finally gathered everything I need to get a new reef setup. I have a 65 gallon rimless tank. I test ran it for about a week or so in the garage before moving it to the living room. It was perfectly level on all corners/sides in the garage when full, however admittedly i didn't level it when empty and the floor is really unlevel in the garage. I have it staged in its finally location in the living room now with no water and just live rock and when I checked the level its way out of level. The tank is on a concrete slab and the floor is very unlevel. So an obnoxious amout of composite shims later I finally have the tank as level as I can get it. My concern is that I literally had to use a ridiculous number of shims to achieve a level tank in the worst spot about 5 or 6 stacked under the stand. Is this too many shims? The tank does have a rubber leveling mat. Im just worried because I'd like to get the tank wet soon but I want to address my concerns before it gets filled. Also if anybody wants to assist me with a means of calculating how much saltwater to mix based off of my tank dimensions and live rock and sand that would be great.

 

[MadReefer]

Don't take my word on this but don't some people use some type of rubber mat under the stand to help with that problem?

 

[jd120988]

Don't take my word on this but don't some people use some type of rubber mat under the stand to help with that problem?

I know I've seen some guys doing that but I don't know if that's going to help for me. Its about 3/4-1 inch out level in one corner. I do have a rubber leveling mat under the tank itself though.

 

[Mark_C]

That many shims seems to put a lot of structural on/off pressure to the base and may start digging into that hardwood.
If its that unlevel and a rubber mat wont do the trick, what about some of the higher end rubber mats made for underneath gym machines? I'm not talking the cheap foam ones, I'm talking the proper gym type 1/2 - 1" thick things.
Or, run a base of the home gym foam type mats as high as needed and drop your rubber leveling mat on top.
I wouldn't trust the tank leveled as is.

Here's my anecdotal experience...
I put in a toilet last year. The floor was pretty un-level. I used 8-9 shims under it to level it.
3 weeks ago I replaced the toilet as it started to develop shallow cracks in two places, both around pressure areas where the shims were.
Cracks literally went from the sides of the shims at floor level up and over the rim of the cistern.
Leveled the floor this time around.

 

[jd120988]

That many shims seems to put a lot of structural on/off pressure to the base and may start digging into that hardwood.
If its that unlevel and a rubber mat wont do the trick, what about some of the higher end rubber mats made for underneath gym machines? I'm not talking the cheap foam ones, I'm talking the proper gym type 1/2 - 1" thick things.
Or, run a base of the home gym foam type mats as high as needed and drop your rubber leveling mat on top.
I wouldn't trust the tank leveled as is.

Here's my anecdotal experience...
I put in a toilet last year. The floor was pretty un-level. I used 8-9 shims under it to level it.
3 weeks ago I replaced the toilet as it started to develop shallow cracks in two places, both around pressure areas where the shims were.
Cracks literally went from the sides of the shims at floor level up and over the rim of the cistern.
Leveled the floor this time around.

I appreciate the suggestion. Im not going to rush any changes just yet. I did post this on reef2reef as well and received a few responses that it would be fine and its normal but to only fill the tank about quarter of the way up and check for level again and to adjust as needed. Im not super concerned about the flooring as its padding then concrete slab right underneath it, although I didn't consider your point of the structural pressures. It makes me wonder though if I should maybe shim between the current gaps to reduce the stress on the already shimmed sections more. The tank definitely was level in the garage with just the leveling mat and the floor in there was even worse than where it's at now and I didn't use any shims. If I were to do the mats that you were talking about, with the gap I have being mostly on the rear of the tank, wouldn't the mats raise the entire tank up too much still? I mean I'm nowhere near an expert of any kind at this but would that compensate properly on all 4 corners considering the difference in heights being so drastic corner to corner?

 

[jd120988]

Also mark_c, are you the gentleman who lives on the other side of brick by Walmart? If so I believe I picked up a bucket of dry rocks from you a few years back.

 

[Mark_C]

Yep.
Currently have a bunch of live rock if you need any. $0 per pound.
Didn't you pick up that giant shelf piece?

 

[jd120988]

I'm good at the moment, the gesture is very much appreciated though. There was a decent sized shelf piece in there and some others varying in size. I never got around to setting that nano tank back up though so I passed them on to someone else recently in the chain. I decided to go bigger with the 65 this time around.

 

[Mark Shelly]

I had a carpet under my 65 gallon tank. The cabinet floor was on the carpet and bowed up, which in turn made closing the doors harder. Worse it would shake as I walked near the tank. So a material that settles under a higher load may not always be the best. If the floor is flat, but slopes, it might be best to have the tank on a slight slope, but fully supported on the sides. Also, the sides usually transport the load to the floor on most stand designs. The horizontal member in the back of you tank does not need to be supported as it supports no vertical load. I cant tell about the front but if it has doors it probably doesn't either. Also the center of the end panels, if solid, could have a gap. Shims in that area should only fill gaps but take no load (in my opinion).

65 Gallons of saltwater is needed to start at a minimum. While you will loose some volume due to sand and rock, it is less than it looks. You may need more for a sump or canister filter (I used one on my 65 gallon tank). Plus, it is often a good idea to have extra water on hand.

 

[jd120988]

I had a carpet under my 65 gallon tank. The cabinet floor was on the carpet and bowed up, which in turn made closing the doors harder. Worse it would shake as I walked near the tank. So a material that settles under a higher load may not always be the best. If the floor is flat, but slopes, it might be best to have the tank on a slight slope, but fully supported on the sides. Also, the sides usually transport the load to the floor on most stand designs. The horizontal member in the back of you tank does not need to be supported as it supports no vertical load. I cant tell about the front but if it has doors it probably doesn't either. Also the center of the end panels, if solid, could have a gap. Shims in that area should only fill gaps but take no load (in my opinion).

65 Gallons of saltwater is needed to start at a minimum. While you will loose some volume due to sand and rock, it is less than it looks. You may need more for a sump or canister filter (I used one on my 65 gallon tank). Plus, it is often a good idea to have extra water on hand.

Unfortunately the tank is not just on a slope but also uneven on the sides. The left side, if facing the tank is lower than the right side. When I leveled it I shimmed only the 4 corners until level on all sides and corners.Then filled the gaps around the stand just to fill the gaps (not load bearing in any position) because I read that suggestion on r2r somewhere. So essentially the load is only on the corners and thats where I did the leveling. Are you saying that the left and right sides of my stand are also contributing to the load bearing meaning not just the corners? The back is open so I know thats not for support and the front does have doors so I doubt its for support either.

 

[Goodair]

You can try making a platform with plywood and have one side 1" higher than the other. Asthetically, it wont look good (unless you put some extra work into trying to make it match the cabinet) , but 1" is alot to rely on shims.
Pic is not to scale and the amount of legs is just a concept, im not sure how often you need to space them out.