Advice on DIY 90-P stand

[Grotevos]

So I'm building a cabinet for a 90p out of plywood. It will be 120 cm in length because it's replacing an existing cabinet and if I ever feel like it in the future I can switch to a 120p. I'm using 18mm high quality plywood. Here's a very crappy mock-up of what the 90p on the cabinet would look like. Cabinet is still in progress.

Now as you can see the filter Is a very tight fit (and yes please roast me for going for the eheim 5e 600t) and even though the filter isn't touching the sideboards I'm concerned about resonance.

So I'm thinking maybe I should leave out the sideboard on the left but then I lose some support. Or I could use soundproofingfoam but I don't know of that would prevent resonance because the filter is such a tight fit it would actually touch the foam. So what do you think? Should I be fine without one less sideboard or should I keep it and try foam?

Sorry for the crappy english btw.

 

[MartyK]

How much room do you actually have on the sides, looks like it can't be more than 18mm based on the plywood? The thickness and weight (density) of sound proofing you need depends on the frequency of the noise or resonance - lower frequency will require thicker and heavier foam or even vinyl. Hard to know exactly what you would need without getting the filter up and running. I have found that isolating the filter from the stand has a much larger impact than sound proofing and I usually do that by raising the filter up on a platform of foam. This works for pumps too like for an internal return pump in a sump or external pump in a water change station.

The other thing that comes to mind with this is if you ever need to replace the Eheim 5e 600t, will any other filters fit in that space?

 

[Grotevos]

How much room do you actually have on the sides, looks like it can't be more than 18mm based on the plywood? The thickness and weight (density) of sound proofing you need depends on the frequency of the noise or resonance - lower frequency will require thicker and heavier foam or even vinyl. Hard to know exactly what you would need without getting the filter up and running. I have found that isolating the filter from the stand has a much larger impact than sound proofing and I usually do that by raising the filter up on a platform of foam. This works for pumps too like for an internal return pump in a sump or external pump in a water change station.

The other thing that comes to mind with this is if you ever need to replace the Eheim 5e 600t, will any other filters fit in that space?

I haven't measured it but I don't think it's more than 1 cm on each side. I'm also leaning towards removing the board on the left. It's just not practical and like you said, even if I try and soundproof it I won't know if it worked until after I get everything up and running. And if it doesn't work it will be too late to remove the board on the left because everything will be glued and screwed into place. Unfortunately I can't just change the width of the compartment because I'm reusing the doors of the cabinet it will be replacing (to fit the aesthetic in our living room). I think it should be sturdy enough without the extra support but unfortunately I'm not an engineer. I'm just afraid I'll be worrying about it collapsing all the time.

An oase biomaster 850 would also fit, they are actually smaller but ironically I decided against one because a lot of people seem to be complaining about their noise levels..

 

[MartyK]

I have built plywood stands for 29 and 40 gallon tanks (110 and 150 liters) out of 12mm plywood without a center brace and only doubled-up sides and front braces. That stand is very overbuilt for both a 90p and a 120p assuming they're not super tall tanks so I think you can safely change to just three supports; double thick plywood if you want to feel very safe. Then you have a lot more room for soundproofing if you need it and won't need to worry about the filter rubbing against the stand or foam. This assumes you can change the supports and still reuse the cabinet doors (which is a brilliant idea!) without any issues.

 

[Grotevos]

Reusing the cabinet doors should be ok because in the existing cabinet there's no support between two doors anyway. I'm going to leave it out and use it to double the support at the 90 cm mark. Thanks a lot for the advice, exactly what I was looking for!