Cheap efficient insulation material advice

[Turn7]

Long story short, Im trying to provide my aquarium with the best quality water I can provide. This necessitates having a water butt for aquarium water preparation outside.This will be heated to the same temp as the tank - 25.6 degrees.
Obviously, Id like to try and keep this temp constant and not waste energy keeping it there.

This will be a 250litre butt and is a squarish design. I plan to build a "shed" around it and fully insulate as best I can.

Any advice on whats best to use in terms of £ cost vs effieciency.

Current thoughts are 150mm polystyrene, but Im open to ideas.

[Busa mav]

Then I would also consider backing it up with a layer of the latest space blanket style insulation products, provides a seamless layer which helps avoid heat loss.

[Turn7]

I plan to wrap the butt in foil before hand....

[Muncher]

I would be wrapping it in space blanket foil insulation and then 150mm or thicker Celotex, with all gaps fully sealed with expanding foam. I would also pay attention to anything going into or out of the tank and any supports the tank is sitting on.

[Turn7]

Muncher, thats about where I at. Ecept Celotex is dear as an 8x4. Im thinking Jab or even straight 50mm polystryene to give 150mm....

[dirkgently]

To be honest the Δt won`t be that big, 150mm Celotext should be more than ample.

[Busa mav]

Look at king span seconds if you are trying to save £££ on the board.

I would still go or a final external wrap of the space blanket , the very outer most covering.

[Turn7]

dirkgently said:

To be honest the ?t won`t be that big, 150mm Celotext should be more than ample.

The what Dirk ?

[Muncher]

An 8x4 sheet of seconds will probably be less than £20, there is a lot of seconds about as its so easily damaged.

[Turn7]

Good point, ta.

[Mr GrimNasty]

Don't forget to insulate top and bottom too!

[Turn7]

Mr GrimNasty said:

Don't forget to insulate top and bottom too!

Nope, already in my mind.....

Sit butt on top of insulation and have lid of "shed" insulated to same depth...

[Dr Mike Oxgreen]

Wouldn't it be cheaper to buy R/O water from your local aquatic shop as and when you need it?

[Turn7]

Dr Mike Oxgreen said:

Wouldn't it be cheaper to buy R/O water from your local aquatic shop as and when you need it?

Not really.

I change 250 litres weekly, and RO would also remineralisation - takes time to settle, so needs a butt.