hi all

a bit about myself. i am an old time koi enthusiast with new drive.

i have been keeping koi for roughly 14 years now but so far they have been tank koi and not anything close to the kind of show koi i see on here.

my enthusiasm waned a bit over the years, but i got some new drive and i will be starting my pond setup shortly.

for now its in the planning stage. but the basics so far, it will be 1.5m(W)X2m(L)X1.5m(D) making it a 4500L pond.

now i have some questions based on filtration for this size pond.
what size filter and pump do i need? i had a pond previously when i was younger and had a basic pump that did about 1500l/h and a home made bio filter which did a great job, but this pond is now bigger and i would like to do it properly. is there some sort of calulation on size of filter and pump? also if i have a biofilter do i need mechanical filtration? i notice a lot of guys have a sand filter and a bio filter.. also, where do i fit the UV filter? is it before or after the pump/filter?

i want to do this properly this time as i plan to spend money on better quality fish this time around.

Hi u3
Welcome to the forum, just the right place to learn.   When you post photos of your setup we will be able to advice you on the way you should go.  

As I understand he doesn't have a setup yet.

Koi is addictive especially in the summer months.

4500l isn't very big but its a start.
My 1st one was 4000L.

Well before the discussion about the pumps and stuff starts.

Are you going to use a bottom drain?

or are you going to suck from the pond?

Bottom drain is advised then you can use a submersible and safe on power.

thank you for the reply nardus. you are correct, i do not have a setup yet. and with the plans for moving house coming up recently i have decided not to spend too much on this place, so the pond i am going to be setting up now is not built in, but rather a bit of ingenuity and creativity, but causes some limitation.

i planned to go with a bottom drain on the built in pond, but i the filter would have sat higher than the bottom drain and i wasnt sure if there would have been enough force to push the water through the pipes up to the filter.

but that i will work out for the next pond once we move into a bigger place.

for now, i found a water reservoir/catchment tank that is broken at the top and the place that had it is no longer using it. so i asked them if i could take it and they said yes..so i plan to cut the top off and use the bottom half as the pond. its neat, its big, it holds water and it is free. just needs a few things to make it work. like an overflow outlet. which it already has at the top half which i will just relocate to the top of the bottom half. and it has a drainage tap.

Now i have a few questions, i want to add a pebble type bottom for the pond, but i know to have the flow rate at eh bottom work well it needs to be void of interference.

so i was thinking would it work if i have a sort of grid that was held about 5cm above the bottom of the pond that the pebble would lie on. and then the dirt/sediment would filter through the pebbles go to the bottom where the water circulation would direct the sediment to the submersible and get pumped out into the bio filter..
or will that not work?il make a quick paint sample to indicate what i am thinking

this is what i am thinking.
what do you guys think? is it a good idea? or bad idea and will cause more headaches and issues?

I don't think that's a good idea.

Can you take some pictures of the tank because I am not sure what we are dealing with here.

If it is a jojo tank it can work.
Not ideal and definitely not perfect.
But it is a start.

yes its those jojo tanks.. its a massive 1. i know its not ideal. but it is a good start and i really want to get started already.. the koi i have lined up are in a tank..and not growing like they should because they lack space.

once its cleaned and setup i will take some pics and post it

do u know how many litres it will take?

Anything will be better than a tank.

I am just interested to know how the tank is cut?

vertically or horizontally?

well cant say horizonally or vertically since that could change on how the tank will lay..lol.

but it will be standing upright and cut across its width not length.
so the top will be taken off

as in my drawing you can see it will be the round base used as the pond.

ok good.

How deep will it be?

1.5m deep. but, if the layout i have planned works i might make it a bit deeper..

but this all depends once i get the chance to actualy start setting it all up

ok cool keep us updated.

will do, thanks nardus for your input.

well after weeks of waiting, the release documents were signed and i could go fetch the water tank.

this is on the day of pickup:


i totally under-estimated the size of the tank and the effort to move it. It was the funniest thing ever moving it though and experiencing the looks from ppl and smoe ppls reactions.. 1 guy at a stop street saw me turning and reversed and turns into some driveway to get out of the way..lol..

now, i am coloured and live in a coloured area so the comments some ppl made were funny as hell..only found on the cape flats..
the 1 man at a bus stop said loudly to no1, "Daai's n Fok#$%N groot water blik" i couldnt stop laughing..i drove home, all of 10km at 20km an hour.

this is the tank finally home and offloaded:


and this is where i plan to cut it, using the bottom half as the pond:

it will be a diameter of 2.16m x1.65m deep but obviously not filling right to the top, so it will be +-1.6m deep leaving me with +- 5864 litres

does this help give my earlier drawing more context?

Hi.

Ek sou ook my gat af gelag het.

I would rather cut it vertical then you will have 2 ponds?

I heard it would be better as I also wanted to do something similar at one stage.

I cant remember why it would be better tho.... 

you ant cut it vertical. since the top is not sealed. the top has a big hole it in where it collects rain.
Plus this one is cracked at the top too..o it wouldnt work. plus then it would need to have supports put on the side since its round and it wont be nice an deep.

i cant understand who would have said its better, yes it would have given more surface area, but no way it would have been 2 ponds and no way it works out easier..

im so excited to get it done... cant wait for some free time to work on it

are you not going to put it in the ground?

then you can support it with the ground.

But doesn't matter. I will still place it in the ground so when you are done you will be able to see them better.

no, it wont be going all the way in the ground. i have a son that runs around all the time and would constantly want to play there and i feel safer if the level of the pond is above ground. plus it saves it from all the crap that blows around into my yard from going into the pond..

No I agree not all the way into the ground maybe just about 500mm above ground would be great.

that way you will have a great view of your fish and it will be pretty safe.

haha, i am actually going the other way around. 500mm under ground and 1200 above.
going to have a bench and plants and things around it.might even paint the exposed part to make it look more natural.

hi nardus, do you know how to calculate the force that the water will push through a pipe?

the tank is being cut at 1.7m and will be filled to 1.6m deep.
this makes it over 5810L the bottom drain /outlet sites right at the bottom of the side wall and i was wondering if the force will be able to push the water up a 50mm pipe the full 1.7m?
if yes, im thinking i dont need a pump. let the force pushe the water into the filter then the filter will run into the top of the pond.
the layout will be something like this..ignore the top part of the drawing.. thats what im thinking about for a possible solution so that the pump is not in the tank.

ignore the scale. this is a rough drawing. lol

finally up and runnin.

the tank is in the ground, the filter is done, the pump is connected, water is flowing and fish are in..the bio filter is starting to get some nice build up and im sure teh bacteria aer growing fast.. had some water from my inside tanks bio filter thrown in to help it along.. its been running for 4 days now and the water has started to go a bit murky, but not too much.its covered with shade cloth that lets some sun through but not too much to let the water go green..

it is by no means done yet. the tank needs to be painted, the garden edging needs to be done and then the permanent wiring needs to be laid.
for now i'm running the pump from a lead plugged in in the kitchen.

pics to follow. busy uploading them now.
took a few months, but the last 2 weeks was the most productive. the last few months were just about getting parts and fittings and working out best options within the limited budget.

its not all to my original plan, but it is working good..

instead of going 500mm underground, i went 800mm+- its now just under 1m above ground. its the perfect height, i have 2 old tree stumps placed on the side that my son climbs onto and stands and looks at the fish.

instead of putting the return pipe thru the wall of the tank it currently goes over the top. this will change after pay day.
i also did not add the circulator or direct the water to the bottom of the tank. i think the pressure will not allow the gravity feed to get water in, so i left it as a waterfall type return. might change in a while...working on making a little venturi system.

also scored with some nice big koi, 40-50cm..they are huge and are very shy and skittish at the moment, but i think thats because of the move they need to start to trust me still. they dont feed while the tank is open or while we watch.