Simply Koi and More Koi

hi eveybody, i need your thoughts , i,m thinking of making my pond deeper at the moment its 10.5 meters long and 7 meters wide but shallow, one area is 1.6 meters deep but the rest is only 60 cm deep , living in the tropics depth is not much of a problem but it would be better deeper . what i,m thinking of is cutting out the floor and taking the whole thing down to 1.6 meters. now i,v got 7300 gal but if i take it down to 1.6m it would give me 20000 gal .question do i make the floor flat or can i make it dished . what i was thinking was making the floor into 4 dished areas<like an egg carton> with a bottom drain in each section or is flat better??? then i,v got to build another filter chamber to cope with the extra water is a series of round chambers better than a conventional square multibay ??? comments please . regards john

If the drains are aerated then you can have a flat floor. Rather than go to all the trouble of digging out though could you just build walls up to increase the depth? I'd say round chambers were slightly better as each can work like a mini vortex but square ones make better use of small spaces and can work just as well.

hi eds, thanks for reply,can,t build it up because 2 sides of the pond are right up to the house walls and the water level is same as house floor and the other side has a huge waterfall, also i dont think the pond floor is strong enough, thats another reason i want to dig it out i can make the whole thing stronger . i,v got 1 existing airated bottom drain i bought in the uk but cant get anymore. what they do out here is build a 30cm square sump in the floor with a very strong plastic grid over it then a 4 inch pipe going to the filter, thats why i was thinking of dishing the floor. the advantage of it is it cheap the plastic grids cost about 50p each as opposed to expensive airated bottom drains. i can get large flat air diffusers maybe i can fix 1 over each grid leaving a gap around the edge. my existing filter is a vortex then a 3 bay filter each bay is 110 cm square by 100 cm deep plus 1000 liter trickle tower.this more than copes with existing 7300 gals but if i build another filter how big do i need to make it to cope with 20000 gals. I propose running 2 bottom drains to each filter bay. hope i,v not confused you too much. regards john

Not confusing at all mate. In your case I might hedge my bets and bench the floor just in case.

If you think the current filter copes well with your current pond then doubling the pond might mean doubling the filtration! Your other choice might be to take one or two of the bottom drains and pump them over a larger shower filter as they are very space efficient.

Ed

Hi
I know a few people out there say you must have the gap between the dome and base set up right to get the current pull through the drain.I think Waddy has done calculations and figures to back this up,this may be true. For the last year my dome has been off my drain,not got round to reconnecting it.I have a 8inch flat disc pumping out 50lts of air sitting on the edge of the drain.Apart from the dreaded weed holding some waste up,the btm is clean.The vortex always gets a good build up of waste ,lumps of poo and fine bits oh and the one 4inch shiro who went for a little adventure.
Maybe i got away with because my pond is almost square has quite a strong current and a little overstocked so plenty of tail movement.
John maybe like Ed said if you have a couple of drains with the grid over them being pumped to showers and an air diffuser next to them you should get enough pull into the drains.Not sure about slope btm it may help but if you look at a vortex,very steep btm and smooth but crap still sticks to it and dosent drop to the centre.
I think you need to run all your drains to seperate filters.
Darren

hi, thanks for the ideas guys i like the idea of showers but dont quite know how i,d feed them from bottom drains presumably i,d have to feed the drains into a box then pump to the top of the shower ?? and if i,m going to do that may as well feed into a 3 bay filter, then if i need i can tee off the return and run through a shower. i think better to run 2 drains to 1 filter because when i built the existing filter i had to fit an extra feed cos it was pumping dry. i use an atman<german>sub pipe pump and its really good and i,v got a spare so ok for the new filter . it pumps 25000 ltrs per hour and is only 50w . my existing shower is just a very large plastic tank 2m high by 1m wide full of oyster shell, but it means i can hide , unlike baki showers. the other thing i wanted to ask is how do you guys return the water ? at the moment i,v got one large ventura the old fashioned type made from pressure pipe,but if i,m going to have more they are too ugly , do you use swimming pool types that fit flush to the walls ? . i had thought about housing the venturas in the pump chambers in and running them through the pond wall or have you got a better system ? the visual aspect is important because all my house walls are glass and every room looks onto the pond. regards john