Gravity drain pond

[Will82]

Hi everyone

ive searched high and low but i just cant get my head around some things. i was hoping someone can set me straight! please!!!!

I want to build a pond entirely raised on an existing concrete plinth around 6x6 ft by around 3ft deep. I was going to build from 100mm dense blocks on their flats and insulate both sides of the wall with 50mm Poly sheet. Would this be no good?

If it is ok, ive been looking at these fishmate gravity filters, and was thinking of having a bottom drain. But do you still have to have a pump inline somewhere. or can the weight of the water just cyclce itself through the filter?

Your advice is much appreciated

Will

 

[addy1]

Welcome to our group! Will

How cold does it get there? To have the water run through a filter you will need a pump in line.

 

[j.w]

Will

 

[Waterbug]

I want to build a pond entirely raised on an existing concrete plinth around 6x6 ft by around 3ft deep. I was going to build from 100mm dense blocks on their flats and insulate both sides of the wall with 50mm Poly sheet. Would this be no good?

Might be OK. If I understand correctly "dense block" is solid concrete, no voids? If true there's no way to add steel reinforcement bar, we call it rebar. Thats what keeps everything together when the block cracks...and it will crack. At least that's how we do it in the US. I don't fully understand your building practices.

So whether it's "good" or not depends on how long you want the pond to last. Without rebar it could bust as soon as you fill it, or could hold for several years, or it could last 100 years. But the risk is much higher. With rebar the risk goes down.

If it is ok, ive been looking at these fishmate gravity filters, and was thinking of having a bottom drain. But do you still have to have a pump inline somewhere. or can the weight of the water just cyclce itself through the filter?

A pump is always needed unless the pond is stream fed, which this one isn't. Bottom drains really require some studying to get right. Before buying I suggest continuing the path you're on...learning and research.