400 gallon plywood aquarium. 600+ gallon system

[Mr_Stian]

Hello everyone.

First real thread here on this forum. I am in the beginning of my plywood aquarium build and would like to use this thread as documentation on the build, but mostly to get feedback and help from this large community.

Today i have a 480 liter aquarium with a sump in the room below. I have wanted to move this to the basement, and when the plan to refurbish this came up i decided to build my own aquarium out of plywood. The basement will be a combined small home theater with the front viewing panel on one wall.

The tank itself will have an outer measurement of 225x90x90cm (I am from Norway, so hope that the metric system will work). It will be built with 3/4" plywood, and i was going to almost copy the same method as "The DIY King" until i read AlexG's thread on his 720 gallon tank. He got some issues with the back and sides bending. So i am still a bit uncertain on how to do this.
My thoughts as of now is to build the tank on the same principle with 3/4" plywood and use this also as a brace, but also to brace the rear with 2"x4" wood. any other sugestions?

Regarding the sump i will incorporate much of the same setup as i already have today with a refugium, separate tank for waterchanges and areas with live rock. Only difference is that it will be a bit bigger than the system in use today.

On the technical side i will use 2 no name LED lamps (china) and a large DIY LED light fixture. I have a full Apex system with the apex WAV pumps. I will also make a surge tank to create random movement in the tank.

More info and progress will follow.

A few pictures of the build so far. The stand has been further reinforced from when the pictures where taken.

 

[Mr_Stian]

Some pictures of the tank i have today and the sump room.

 

[Mr_Stian]

I want to start to order the glass, but i am not sure on how big this needs to be. The front panel will be 225x90cm. How large do the frame need to be? I was thinking of using 2"x4" for the top bracing. 2" if 5 cm. So a "cutout" of the front panel with a frame of 8cm would give an extra 3cm for the glass. So my question is this:

Is 8cm enough for the frame on the front panel? This is a little more than 3"
Is 3 cm enough for the glass to overlay the frame? 1,2"

Se the picture for a quick illustration of the front panel.

 

[maroun.c]

Plywood builds are always great. Love the dimensions although 90 CM high might make maintemance a bit more difficult. My tank is 81 cm high and is a bit difficult to reach the bottom or especially the lie rocks in the back side. Then again you guys in Norway tend to be tall
Sorry can't answer ur question is I have no experience with this. Am sure others will chime in.

 

[Mr_Stian]

Today i collected all the plywood. Glass was delivered a few weeks ago. PVC ordered today and the valve for the surge tank! Really looking forward to start this build. Now i am only waiting for the available time. Hopefully i can start this weekend but not sure.

To complete this build i only miss the glass for the sump and surge tank. I have been trying to find some very cheap used aquariums locally, but i cant seem to find anyone with close enough measurments. So i might have to order glass and just make them my self!

 

[Muttley000]

Hi, I am anxiously following along as I plan to build a large plywood tank in my basement as soon as I build an addition on the house to get my wife's laundry out of the way! How thick did you go on that big piece of glass? From the threads I've read the frame and glass overlay are likely OK, more is always better though and I have yet to install glass in a plywood build myself. Hopefully @AlexG stopps in amd can give you some reassurance. I hope you will detail your surge box in this thread also, what type of valve did you buy? What method are you doing to seal the tank? I built a 270 gallon plywood sump using the pour method and it worked great,,but I won't be able to tilt a 10' long box to fillet the corners properly in my basement so exploring other methods.

 

[Mr_Stian]

The glass overlay will most likely be closer to 5 cm in my new design. i see no obvious reason to have it any smaller. The thickness on the front glass is 19mm. I could probably go down on thickness but it makes me sleep a lot better. The glass has polished edges. and ways 80 kg!
I will keep this thread updated with everything related to the aquarium, so there will be updates on the surge tank as well. I have ordered this valve: https://www.ebay.com/itm/HSH-Flo-2-...h=item1cb82d3c31:g:bIwAAOSwj85YNPMY:rk:1:pf:1
It is a 50mm actuated valve with 230V connections. Normally closed. This means i can very easily operate this from my Apex. I am hoping to have around 100-150 liters in the surge tank. Going from 50mm to two 32mm outlets. I have a few ideas to have this operate as silently as possible and with as little bubbles as possible. I will do some tests as soon as i have the valve.
Regarding the sealing i am using Pond armour Pond shield in black.

I can also say a bit about the sump. It will consist of at least 4 different tanks. Not including the RO/DI water tank. There will be a tank only used for water change. This is about 150 liters. Then i have a 180 liter tank with only live rock and sand. And the last two will be two standard sumps underneath with all the technical equipment. Including a large chamber for refugium. The reason for having two is to be able to remove them without removing the supports for the main tank. I do not have these yet so i do not know the size yet. but i was hoping for around 250-300 liters each.

 

[AlexG]

Hi, I am anxiously following along as I plan to build a large plywood tank in my basement as soon as I build an addition on the house to get my wife's laundry out of the way! How thick did you go on that big piece of glass? From the threads I've read the frame and glass overlay are likely OK, more is always better though and I have yet to install glass in a plywood build myself. Hopefully @AlexG stopps in amd can give you some reassurance. I hope you will detail your surge box in this thread also, what type of valve did you buy? What method are you doing to seal the tank? I built a 270 gallon plywood sump using the pour method and it worked great,,but I won't be able to tilt a 10' long box to fillet the corners properly in my basement so exploring other methods.

Thanks for the mention @Muttley000. I was exchanging PMs with Mr_Stian about this plywood setup. It looks like this will be a really nice once it is up and running. Glass installation is nerve racking because of the short window of time available to complete the job. I found that making a few practice runs helped out a lot to ensure that you and any volunteers you might recruit know exactly what to do during the actual installation. Battery powered or electric caulking gun is almost a must have when installing large pieces of glass.

 

[Mr_Stian]

An electric caulking gun is a must!

Did you use anything to distance the glass from the plywood so that you would not squeeze away all the silicone?

 

[BZOFIQ]

subscribed.

 

[AlexG]

An electric caulking gun is a must!

Did you use anything to distance the glass from the plywood so that you would not squeeze away all the silicone?

Yes and its important to use spacers to ensure you have an even seal thickness between the plywood and the glass. I used small pieces of plastic zip ties as spacers for my glass installation. I used a small dab of RTV to put the spacers in place in the middle of the glass overlap of the plywood before installing the glass. When i was researching spacers I found someone that had major issues with tank seals because the spacers were just sitting in place and they were moving out of place when the RTV was applied. When the RTV is applied it should be put in place as one thick bead to minimize air bubbles in the seal, which can be accomplished by applying a lot of RTV slowly which makes it pile on itself. There has to be enough to cover the seal area between the plywood and glass completely. My very first youtube video overviews the glass installasion for my 480 gallon reef tank.

 

[Mr_Stian]

Thanks AlexG. I remember that video now.

Did you wait for the RTV on the zip ties to fasten, or did you just put these in place first and then put the RTV for the glass after?

 

[AlexG]

Thanks AlexG. I remember that video now.

Did you wait for the RTV on the zip ties to fasten, or did you just put these in place first and then put the RTV for the glass after?

I did let the zip ties setup for a while at least 30 minutes. I wanted to ensure that they would not move when the glass was laid down for its final install. I also cleaned the bonding surfaces with rubbing alcohol thoroughly before the RTV was laid down to ensure there was no dirt or dust on the bonding surfaces of the glass or the epoxy on the plywood tank.

 

[Mr_Stian]

Looks like we are on the same page.

I did some more work on my stand to get this ready. And it seems like i have some difference in the measurements of the 2"x4" beams. There are 1-2mm hight difference causing some high spots. I will grind these down so that it is level, but should i use some sort of styrofom underlay?

My idea was to use a thin sheet of plywood and glue some pink styrofom onto this. So if it is still not 100% flat this would absorb this.

Any input on this?

 

[AlexG]

Looks like we are on the same page.

I did some more work on my stand to get this ready. And it seems like i have some difference in the measurements of the 2"x4" beams. There are 1-2mm hight difference causing some high spots. I will grind these down so that it is level, but should i use some sort of styrofom underlay?

My idea was to use a thin sheet of plywood and glue some pink styrofom onto this. So if it is still not 100% flat this would absorb this.

Any input on this?

I spent a lot of time on my stands making sure they were level. I added a plywood cap to the top of the stands but I did not use any Styrofoam in between the tank and the stand for my tanks. As long as you have two flat surfaces meeting that are close to or are level then you could use foam. The main concern I had with my tanks was preventing torsion or a twisting of the tank while it was sitting on the stand.

 

[Mr_Stian]

As you can see on the attached pictures there are some hight difference between the beams. There is also a difference on the front to back beam. In the front it is to high, but in the back it is to low. This is the reason for using something that can absorb the difference in hight. I will try to minimize the difference, but where it is lower it is difficult.

 

[vegamedic]

a jackplane and 10 minutes will take care of that height difference for you

 

[Mr_Stian]

I have borrowed an electric jackplane and tried this today. It worked, but there are still some small imperfections that i am going to sand out tomorrow.

All of the missing PVC parts arrived today. So now i think i have everything needed to complete the build. Now i just need to find some time to do it!

Some pictures attached of the PVC and the stand. The stand will have 2 more vertical 4"x4" beams on the rear. And yes, the speakers will be boxed inn to prevent corrosion. And all the wood will be painted using bathroom membrane.

 

[Mr_Stian]

The stand is now level and without any major peaks. I will still use a 6mm depron sheet under the aquarium.

I have had two coats of liquid membrane normally used on bathrooms.

This means that the stand is now ready for the aquarium. I have ordered the glass for the two sumps that will go underneath.

Below a few pictures of today's status.

 

[Mr_Stian]

Today I received the actuated valve for the surge tank system. I had to change the valve from "normally closed" to "normally open" as it did not operate just as I thought it would. But not a big issue.
Just hoping that the system will work as good as I hope it does!