hi all

[koimaster]

hi all i am re-building my pond and wondered on peoples views on benched bottoms vs flat i guess there will be a big divide in those that have slopped/benched bottom and those that don't please could you help me make im mind up. as im currently going sloped slightly towards the bottom drain.

[Gazza]

Hi,

I have a flat bottom

I don't see the need for a big bench toward the drain as if you have your set up correct and with an aerated bottom drain and with all the fish movement it should all get pulled down the bottom drain

[koimaster]

you have a flat bottom must be all that sitting down you do gazza

but back on topic surely it helps as a fail safe if you miss calculate max flow of around 2222 gal [give or take for bends] and hour via your 4" pipe

[Gazza]

Hi,

Me sitting down i should be so lucky

The flow down the bottom drain of course does make a difference and if it is to slow you could end up with "waste" in the drain line but this can be purged with your weekly cleaning/water change by just opening the valve after emptying the filters if your worried about that. I know of many ponds which are indeed just have a flat bottom and don't have any trouble mine being one of them and this pond was up and running in 2004 and been OK so far. I have the drain in the middle of the pond and it is an aerated one with a 40ltr air pump and not only does it help with the O2 in the pond it creates and uplift which in turn helps pull any waste down the drain.

Another thing to remember is that we have fish swimming round the pond and this also makes a fair current which also helps with moving the waste around the system and down the drain.

[Brek]

Wasn;t aware there was a divide on the subject, my bottom is also flat, and keeps very clean, I did it that way as I lined mine in jabfloor insulation and it was the easiest way to do it, I believe having an incline toeard the BD's also works.

[ageinghippy]

I`m agreeing with the others, with an aerated bottom drain, a flat bottom does the job fine.

Brek, when I dug my pond, 20 something years ago, there was no such thing as this jabfloor stuff, nor the kingsmill (sp ? ) insulation boards, they hadn`t been invented yet. I used 8x4 sheets of 2 inch thick polysyrene to line my pond. I must have been a visionary I think, thinking about insulation all that time ago. Anyway it worked well, and like the flat bottom, still working today.

Chris (another one)

[koimaster]

i see want you all are saying but i currently have flat bottom i do get some crap around the edges , i also have a air bottom drain and this leading to full bore 4" pipe via one 90 deg bend .
i think im gonna stick with my plan or just bench a slope 2ft away from the sides

[Gazza]

Hi,

Have you thought why you get waste still in the pond is it the pull not enough,drain position,enough air,food the list goes on

I can feed fairly heavy in the summer ( kilo per day) and never get a build up of waste on the pond floor so i wonder if there is a reason for it

[Geoff9]

Hi Koimaster
You could just bench the sides,it works well on my pond with areated drain.

Geoff