How can I reinforce a kitchen cabinet to support say a 90 gal tank?

[Philip]

I haven’t had a tank in 20 years but am thinking about getting back into it

I have a perfect little alcove where a tank would fit nicely and has access to unfinished space below where I can put equipment, a water filter, a huge sump if if I want etc. only problem is it has cabinets built in. I could remove them and store them somewhere, put down some sort of tank safe flooring and a normal stand but the wife isn’t feeling that

These cabinets are plywood not mdf, but they’re not fantastic quality. The top is about 3/4” thick plywood, I could not identify the laminate species. Cherry maybe?

Where I get heartburn is the support of the top. It’s supported on the corners but not the center, with a gap maybe 1/4” above where the cabinet boxes meet

I could shim the top to the cabinet boxes, but I fear that won’t be sufficient

I think my best plan of action is to internally brace the cabinets. All I can think to do is build an internal 2x4 frame inside the boxes, L shape two 2x4 at each of the 8 corners then run a cross brace corner to corner against the bottom of the counter top.

I don’t know if this will be sufficient. And I don’t know if the floor of the cabinet will take that weight. I can double up the floor with marine grade plywood or something, or I can punch the 2x4s down through the cabinet bottoms against the subfloor but I have no way to reinforce that

Am I sunk? Am I over thinking it? Most commercial stands are really quite flimsy so I don’t really know what I need and I’m far from a structural engineer or cabinet maker

Back corner where the wire chase is drilled showing countertop support


center, where the two cabinet boxes meet




Outside view



Top thickness

 

[griss]

Other than the 1/4” gap you mentioned, I think 2x4 reinforcing will work. I don’t have any suggestions but maybe @wvned might have some thoughts.

 

[griss]

Oh, and welcome back to the hobby.

 

[Philip]

Oh, and welcome back to the hobby.

Thanks. I’ve only been a member here for 23 years

 

[Philip]

I have other concerns too, the fish room I have in the basement doesn’t have a floor drain, so a stock tank sump might be a bad idea but that’s putting the cart before the horse
Has much changed? Are people still using playground sand for deep sand beds?

 

[itsjimmystark]

Looking forward to hear the thoughts! I am facing similar issue as my cabinet issue. I am calculation the dimensions of the cabinet so that I can have a clear picture & then I will post the pictures here to ask for advice of experienced fellows. Btw, I just registered on this forum.

 

[kharmaguru]

Because that stand is built into the alcove, I don't think you need any lateral bracing. I'd be tempted to just get a sheet of 3/4 ply and double up the the left, right and center supports top to bottom. Do both sides of the center. Screws and construction adhesive. Long screws right into the wall studs for left and right. Need a little more info on the base construction to determine how far to send your load bearing pieces. Is it just a weak kick plate or is it a sturdy frame?

 

[Philip]

Because that stand is built into the alcove, I don't think you need any lateral bracing. I'd be tempted to just get a sheet of 3/4 ply and double up the the left, right and center supports top to bottom. Do both sides of the center. Screws and construction adhesive. Long screws right into the wall studs for left and right. Need a little more info on the base construction to determine how far to send your load bearing pieces. Is it just a weak kick plate or is it a sturdy frame?

I can’t see what’s behind the kick, there’s a thin decorative piece and I think more substantial framing behind it

I am starting to think as long as I transfer the load from the top to the vertical supports of the cabinet ie fill that gap, it’ll probably be ok. Bracing it the way I want just transfers it to the bottom of the cabinet box that probably isn’t very strong

 

[kfisc]

Perhaps you've already addressed this, but what are your thoughts about the increased humidity in that space?

 

[wvned]

Most commercial stands are engineered to use materials in a manner that exploits their strength. They do look flimsy but I have never seen one fail unless they get wet constantly.

You have to put something inside the cabinet that supports the perimeter of the tank. I would float the cabinet top on this and not even attach it to the kitchen cabinet. Perhaps a 1/4 inch gap between the counter and kitchen cabinet.
This way the kitchen cabinet doent take the weight at all.
I apologize to whoevers pic I stole.
Something like this. The famous Rocket Stand

Except yours doesnt have to be pretty. No one will see it. It just has to be flat and square. Notice the top horizontal sections are 2x6 but the rest is 2x4s.

So you remove the counter. Cut slots in the sides of the cabinets in the middle to pass the 4 parts from side to side. Note: The bottom rectangle distributes the weight on the floor. But it could be built inside the legs. That way it wouldn't be right up against the front and rear cabinet wood.
I believe I might attach the top rail through the cabinet and into 2 wall studs. No wiggle at all.
The cabinets would need the bottoms cut to pass the legs down to the floor.

So you have a 90 gallon tank sitting on a stand with the counter top on it and the 2 cabinets around the bottom as camouflage but they could hold some stuff or equipment.

You didn't mention a sump? If that had to go in it would require the removal of most of the sides of the cabinets in the middle. You would probably have to add some wood to strengthen the cabinets in the middle.
Then you would fit the sump into the cabinets before the countertop is placed and attached to the stand and the tank set.

And depending on how the cabinets are made you could maybe simply remove the front frames and doors and apply them to the front of the stand.

The Rocket stand is overbuilt and has to survive shoves from the sides. If you attached the front and screwed the back top rail to the wall you could get by with two 2x4 sections in each corner as legs.

 

[Philip]

Most commercial stands are engineered to use materials in a manner that exploits their strength. They do look flimsy but I have never seen one fail unless they get wet constantly.

You have to put something inside the cabinet that supports the perimeter of the tank. I would float the cabinet top on this and not even attach it to the kitchen cabinet. Perhaps a 1/4 inch gap between the counter and kitchen cabinet.
This way the kitchen cabinet doent take the weight at all.
I apologize to whoevers pic I stole.
Something like this. The famous Rocket Stand

Except yours doesnt have to be pretty. No one will see it. It just has to be flat and square. Notice the top horizontal sections are 2x6 but the rest is 2x4s.

So you remove the counter. Cut slots in the sides of the cabinets in the middle to pass the 4 parts from side to side. Note: The bottom rectangle distributes the weight on the floor. But it could be built inside the legs. That way it wouldn't be right up against the front and rear cabinet wood.
I believe I might attach the top rail through the cabinet and into 2 wall studs. No wiggle at all.
The cabinets would need the bottoms cut to pass the legs down to the floor.

So you have a 90 gallon tank sitting on a stand with the counter top on it and the 2 cabinets around the bottom as camouflage but they could hold some stuff or equipment.

You didn't mention a sump? If that had to go in it would require the removal of most of the sides of the cabinets in the middle. You would probably have to add some wood to strengthen the cabinets in the middle.
Then you would fit the sump into the cabinets before the countertop is placed and attached to the stand and the tank set.

And depending on how the cabinets are made you could maybe simply remove the front frames and doors and apply them to the front of the stand.

The Rocket stand is overbuilt and has to survive shoves from the sides. If you attached the front and screwed the back top rail to the wall you could get by with two 2x4 sections in each corner as legs.

Plan is to run a 100 or whatever gallon stock tank sump in the fish room below. Concern there being there’s no floor drain. I can elevate the stock tank and run an overflow along the wall to the sewer drain where a utility sink dumps in. I think that’s reasonably safe and I can pump water to the sink for water changes. I have room for fresh and make up water tanks, and I can put a ro/di in there and automate a lot of the things I hated doing with reef tanks

My concern with that bracing is how to spread the load out. If I build it so the bottom rail is along the internal base of the cabinet now I’ve transferred the load to the bottom of the cabinet, which is probably simply stapled to the vertical sides and I can’t transfer the load to anything more substantial

If I cut holes in the base of the cabinet now I’ve pinpointed the load to the surface area of the ends of several 2x4 directly to the OSB subfloor, with no real way to spread that out. The osb probably isn’t that strong.

I could downsize to something like a 50g cube, I can stand on these cabinets and they won’t flex and I’m 275lb, figuring a 50g is 500lbs that’s not much of a stretch

The best solution is remove the cabinets, put down some lvp flooring where the carpet ends, texture the drywall and paint it and store the cabinets in a closet until we sell and get a Red Sea refer tank and stand. Run flexible hose into the basement for the ATO ro/di and maybe a couple extras for auto water changes. The wife does not like that idea. I proposed to put the tank along the wall to the left but she says the room is already too small and that will make it feel cramped

Hopefully I’m making sense. It’s difficult to describe something you can’t see

 

[Philip]

Perhaps you've already addressed this, but what are your thoughts about the increased humidity in that space?

No real concern. In the winter it will be welcome. In the summer we run ac which will dehumidify

We run a whole house bypass humidifier in the winter on one of the two furnaces (second is in unconditioned space so not an option) and it struggles to keep it above 25-30% humidity. It’s a large space with a lot of high ceilings and a lot of volume. I don’t think it will increase the humidity much, it I could be incorrect

I really need a steam humidifier

 

[discotu]

Start from scratch and do it right. Remove the doors and hinges then carefully remove the front panel for the doors. Now would be a good time to refinish the wood with a good water resistant clearcoat. Remove the counter top and confirm it's suitable plywood. If not remove the front trim to save for later. Demo everything else and remove any carpet that might be under the cabinet. Personally i would also push back the carpet away from the base of the stand and have a strip of tile or wood flooring to create a margin for spills. Frame the new stand to the subfloor and the wall studs. This also allows you the flexibility to build the new cabinet exactly to the new tank vs awkwardly trying to fit a tank into the existing space. While its opened up i would run power to the cabinet. Not sure if theres an outlet in the space already or not. If not you can run wire from the outlet on the left and hide it behind the base trim. As a precaution i would also frame the base such that i could epoxy coat the subfloor up to a 2x4 to create a waterproof tub just in case the sump or theres accidentally lclearcut. You have framing done you can skin the front of the new stand with the existing front panel+doors and replace the top trim if it matches the other cabinets.

Then your next project will be a matching built in canopy have fun!

 

[wvned]

I put in a utility sink and connected it through a wall to supply and drains from a bathroom. I route all my drains and dump my skimmate (a 5 gallon bucket) into it.
The stand I posted uses the bottom rectangle to distribute the load to 2 or more floor joists. The floor underpayment does not carry the load. No feet to concentrate a load on the floor. If you build into this cabinet, I would add a bottom caulk the seams with silicone and paint it with white exterior paint.
Then leaks could be contained to the cabinet and a leak detector could even be employed.
A Hydros controller system could give you an ATO, leak detection, skimmate full alarm, heater control (mine runs 9x200w) and a bunch of other possibilities. Controlled solenoid valves and boost pump control. Mine keeps my 100 gallon RODI vat full. It auto flushes the membrane too. It's modular and you add more controllers with ports for things as you need them. You just join them into a wired network that forms what is called a collective. The group of controllers all look like one and are programmed together.

 

[discotu]

The best solution is remove the cabinets, put down some lvp flooring where the carpet ends, texture the drywall and paint it and store the cabinets in a closet until we sell and get a Red Sea refer tank and stand.

wait...are you planning on selling the house in the near future? If that's the case I don't know if I'd go through the trouble.

 

[Philip]

Start from scratch and do it right. Remove the doors and hinges then carefully remove the front panel for the doors. Now would be a good time to refinish the wood with a good water resistant clearcoat. Remove the counter top and confirm it's suitable plywood. If not remove the front trim to save for later. Demo everything else and remove any carpet that might be under the cabinet. Personally i would also push back the carpet away from the base of the stand and have a strip of tile or wood flooring to create a margin for spills. Frame the new stand to the subfloor and the wall studs. This also allows you the flexibility to build the new cabinet exactly to the new tank vs awkwardly trying to fit a tank into the existing space. While its opened up i would run power to the cabinet. Not sure if theres an outlet in the space already or not. If not you can run wire from the outlet on the left and hide it behind the base trim. As a precaution i would also frame the base such that i could epoxy coat the subfloor up to a 2x4 to create a waterproof tub just in case the sump or theres accidentally lclearcut. You have framing done you can skin the front of the new stand with the existing front panel+doors and replace the top trim if it matches the other cabinets.

Then your next project will be a matching built in canopy have fun!

That’s not a bad idea. I could use a flush cut saw and just cut the whole front off then reattach to the stand

 

[Philip]

wait...are you planning on selling the house in the near future? If that's the case I don't know if I'd go through the trouble.

I mean, 5 years or so probably. We’ll have to downsize when I retire and move to a lower cost of living area, most likely.

When I lived in Hawaii I didn’t need a reef tank. I could just go visit the fish and coral whenever I wanted