***The Pond Discussion Thread****

[NickK]

I’ve just upgraded my pump to 30,000 litres an hour from 10,000

I need more action in the main falls

Pics and videos incoming

Ouch, I see a Tesla powerwall and solar panels in the future!!

When you see koi owners, you normally see the pond and fish but the size of pumps, filters and the running costs are seriously high.
Our little 8,000l/h system and 600l/h air takes a fair whack of electricity.

 

[easyrider]

Ouch, I see a Tesla powerwall and solar panels in the future!!

When you see koi owners, you normally see the pond and fish but the size of pumps, filters and the running costs are seriously high.
Our little 8,000l/h system and 600l/h air takes a fair whack of electricity.

It’s variable 45-385 watt...


Old pump, 10,000 lph 85 watt maxed out.... 15w 4000 lph lowest setting

I’ve been running it at around 75%

New pump will give me 12,000 lph at 45 watt... lowest setting with headroom up to 30,000 lph

 

[easyrider]

Bit of a disaster, the Dyke overflowed into my pond making it a tannin murky mess...So I installed a Semi DIY Carbon filter to try and clear the water before spring hits...

10kg Activated Carbon £29 added to a Hozelock Ecocel filter box £39...was up and running in 30 mins...Put the emergency filter in the top reservoir to if it overflows it will just flow back into the pond.

Operation Clear Pond !

 

[NickK]

Me: I'll add some cloverleaf blanket weed killer and put some pond filter gel in..
Koi: *OMG*OMG*OMG* *ACTUNG*ACTUNG* DIVE*DIVE* hide hide hide

So very skittish atm.. they're warming up sunbathing but the pond needs some TLC ahead of the season.

I think I'll need to replace the UV in the filter canister (24W) I also think the 9000l size is probably just on the verge o working with the 4500l pond...

They need a wider depth to the base of the pond too.. currently they're all attempting to get to the bottom of the bottom most point... which has space for 1 koi...

 

[NickK]

Good news. Mrs has given the purchase of a new filter for the new pond (run it on the old one so it matures). Old pond is 4500l, new one will be about 8000l.
Bad News. Boris has stopped all non-essential shops...

So the current initial bill of materials to start is;
EA Varipump 20,000 - this can be varied between 1-100% power. It has 2" connections too and can be run out of the pond.
DracoDrum Solum 16 + standard bio should cope with a 'max' of 16,000lph, so running at 8-10,000lph should be simple enough. It can be switched from pump to gravity fed configurations.

Now I could put a EA EVO30 in immediately, but I have an old TMC UVC that I can use in the interim (although with 1.25" connectors the flow rate may suffer) to support the old canister's failing unbuild UV bulb. I can also use the existing Oase Oxy500 air pump for the bio filter but I will need some media.. thinking 50l of k1 filter medium initially and I can upscale that to 100l later.

The idea is have the filter running and then mature the media/troubleshoot before I start digging holes for the new pond. The existing pump is 60w continous (which is probably closer to 3-4000l/hour nowadays), the new one is max 190W but can be run at 25-30% in the old pond which would be 6000l/hour.

Grr... I may wait to see how the job holds out (given I'm in the probationary period still, with all the virus mess).

 

[NickK]

Told the Mrs the price... and she has agreed a budget that seems workable (with me doing the work!).

first step is getting the filter set up on the old pond.. not being Yorkshire or Scottish but don’t like spending money lol

 

[NickK]

If you are planning a pond - worth checking out this guy's explanation of pipe diameters - it details metric and imperial etc.. and answers why the blazes it's such a pain. Sort of the most boring subject in the universe but also currently the most useful.

I now have a new idea for the plumbing - using 63mm flex pipe will be cheaper for the temporary setup on the existing pond until the new pond plumbing is ready. The heavy duty flex pipe can be bonded into a union joint - I'll also design the whole thing so it doesn't end up being bonded together but use boots or better still unions on the pressure side.
I've also decided that the pump will sit out of the existing pond - so it needs a non-return valve to ensure that the pump will operate after a power cut. The pump itself is not self priming.

Anyway tomorrow is D-day.. ordering time

 

[NickK]

Filter ordered - along with temporary flexible pipe plumbing should arrive next week.

DracoDrum Solum16
DracoDrum Std Bio with 50l of Hel-X 13 media
EA Varipump 20000
Switched junction box 1->5 (drum, pump, air, old pump and UVC)

At full tilt this setup could cycle the entire water in the current 4500l pond at ~13 minutes (in theory), but the pump can be set from 1-100%.. so with that it run to match the current rate (pump is 6000l/h but with pressure filter etc is likely to be running at ~4500l/h). After clarification switching pump to gravity would need a £15 part but they threw that in for free
Max capacity of the new filter, manufacturer stated maximums, 16,000l/h, bio support (@100l media) 15,500l pond which should be plenty for the 8000l pond with some koi in

The idea is to run this in parallel to mature the bio, then slowly reduce the old filter flow rate (just leave it to bung up over summer) and then switch it off completely. I may add a small UVC on the old small 2500l/h pump temporarily - taking the output and then running a small portion through the small UVC I have. I can then switch that on/off using the switch box.

I may install a water level sensor: float-switch-230v-2m-cable to switch off the pump if the pond level drops too much.

 

[NickK]

Next job in Pond2.0 is to make a mood board with the look/design. This afternoon sees some garden tidy up and I'll take some photos.

One idea is to make the pond have a 30cm and 70-100cm depth shelf for the lilies to one side - the koi like to sunbath with their heads under cover of the lilies. I also want a veggie filter and other ideas are possibly a long channel 'stream' or shower.

That will then govern the shape/position of the filter and then I can look at the pumping needs.


If you've not seen Wrighty's DIY channel - makes his own filter kit using welding PVC including a rotatary drum filter, here's the recent bakki stream:

I decent "feeding your koi" without being a marketing video.

Good point about natural foods that they like per season.

 

[NickK]

Just starting to think of Pond2.0's design and plumbing.

Pond plumbing

Extraction
+ bottom drain with 4" PVC pipe, ideal & max flow rate (at pressure) would be 21-24K US gallons, or 79,500-90,800 litres/hour
+ Oase Aquaskim40 with 1.25" pipe, 6-16K l/h flow rate ('ideal' being 8,000 which is bananas). I have one of these already so I may as well use it

A 3" bottom drain would, gravity fed, push a higher flow rate for it's pipe area (thus in theory push crap through easier by itself) any bends reduce flow rate. Also 4" is basically the cost of 3". 4"/110mm bottom drains are more common too.
The top of the vertical rise will have a sweeping 90 T junction - the horizontal goes off to the filter and the open T sitting above water level allows (a) an overflow, a trickle feed in for topup but the 4" pipe also allows you to get a 1" pipe down there to vacuums any crap out or prod any blockage.

The use of a 4" sweeping 90deg or two 45deg should make the bottom drain both maintain flow rate if needed. Without pumping and 8.5 tonnes of water over the bottom surface, the drain will have a decent natural flow rate into the filter sitting just below water level.

The design of skimmer needs a negative level, ie something pulling the water out from the centre pipe. This won't work well with a gravity fed input as the pump is on the output. You want the skimmer to go through the solids filter before getting to the pump. The basket of the skimmer still allows some cack through. I may have to sell that to fund a side wall skimmer (that has an overflow build in) when I sell the old filter and pump. The side wall skimmer has a 3" pipe with 2" overflow. That naturally makes it an easy integration into the main filter line with a tap to limit flow without blocking up.

Mechanical filtration stage
+ Draco Drum Solum16 has two 110mm inputs, two 110mm outputs and a 110mm waste pipe. Think of it as a self cleaning strainer down to 58 microns. Max 16,000l/h but ideally lower. It needs either a fresh water feed (for cleaning spray) or a temporary 3Bar pump from the clean side of the filter (although some cack may still get through and block the spray nozzles). The waste pipe is simply piped to the filter pit floor drain - the pit will have a drain to take any water in the pit through a 3 or 4" pipe to a drainpipe. The waste will be no different to the crap coming off the garage roof.

The input will take the bottom drain and skimmer without a problem - this is gravity fed so it will only take water at the rate the water is drawn out of the output. If the filter clogs, then the water flow will simply stop until it's cleared.

 

[NickK]

Biological filtration stage
+ Draco Bio - a 185 litre box with two 110mm inputs at the top gravity fed from the drum filter output. This filter provides a massive surface area for good bacteria to grow and convert ammonia/nitrites into nitrates. In the filter will be 50 litres of Hex-13 bio media (plastic 'balls') that increases the surface area massively. The filter can take up to 100l of it, but for a 8000l pond this is fine.
The filter media circulates, stopping the water from going directly from input to output. It uses air to push the water up in the centre of the chamber. I'll use my existing 500l/h pump for that. .. water output is through two 110mm outlets at the bottom.

The Bio cycle is simply the nitrogen cycle:
Food -> fish -> Ammonia -> bacteria -> Nitrites (NO2) -> bacteria -> Nitrates (NO3) -> Plants or Algae (or water change).

Bio is one of the most important things as high ammonia or Nitrites (NO2) will quickly kill fish - as waste ammonia from Koi comes from both the gills and through pooping. The majority comes from the gills supposedly. However the bio will not work well without removing the poop before it decomposes or releases further ammonia/nitrites.
The bacteria in the bio section, the walls of the pond, everywhere will convert ammonia and Nitrites into the less harmful nitrates (NO3) which is what plants love.

Now comes the bit that makes the whole gravity feed work - the pump.

Pumping water out of the filter
It sounds odd thinking of it like this but the pump is simply emptying the filter, then the pond is pushing the water in to refill it. Like ezrider - I'll use a variable power pump, but the main thing with pumps is what it's pumping into - that reduces the flow rate. However the water by this stage should be clean so there's less wear and it doesn't get clogged up..

The pump I'll be using has 2" inlet and outlet with a maximum of 20,000l/h without any pipework or pumping the water upwards. They give the pump head height and flow rates for the pro range and by 3m vertically you're looking at 1/2 the flow rate (so 10,000l/h). I will be looking at using slightly bigger pipe - 68.8mm as you tend to get an easier flow rate through bends and once a bio film appears that larger flow rate will reduce slightly - it will still connect to the pump at 2" (approx 50mm) but all the piping will be this larger size.
A 63mm pipe gives a better max flow rate than a 2" pipe (I'd estimate a 63.8mm pipe is about 25,000l/h ideal rate with bends etc).

Next up sterilising the water - ultraviolet clarifiers (UVC)
UVs need time to sterilise the water (both tree water making suspended algae and parasites) that is flowing through them - think of watts of exposure per second. How much depends on how much sunlight, how many fish and how big the pond is (ie flow rate). Also the UV bulbs reduce in effectiveness as they age - so every year they should be replaced to maintain effectiveness.
Now comes the fun part - flow rate. A 110W UV has a 2" inlet and outlet.. However lower powers have only got a 1.25" inlet/outlet. Which is about 12000l/h absolute max in theory. This is far less as the lower diameter has worse flow characteristics and the EVO30 has two 90 degree bends in and two 90 degree bends out. However the EVO30 with 1.25" connections is quoted as 15,000l/h (yer right) for a 30,000l pond. Now I would be happy with 30W (I have a 24W on a ~4000l pond in full sun now) but the flow rate and restriction is concerning.
So one option is to parallel the UVC with a bypass that has a tap to vary the amount of water pushed through the UVC. Also another options is to make that 2 UVC in parallel thus creating a larger pipe area (although not completely double) this would increase the max rate capability without bypass closer to 16,000l/h but slow the water through (thus making the steriliser more effective) during normal flow rates. Any over rate needed can be taken by the bypass. It's better to have a dead bug at a slower rate. Option here could be to run two 15W UVCs or one 15W plus a 25W and then have one on a timer for over night.

There is another reason for considering smaller UVCs in parallel. a big wattage UVC typically has a larger/longer bulb and that means the UVC itself is long. A EVO30 is 98cm, whereas EVO15 and EVO25 are 58cm. This makes it easier to fit into a filter pit without having to have more bends to double back the pump flow. The idea being to maximise pipe area, flow rate and reduce the bends and height increase.

A US paper gives an example: "At an irradiance of 1.2 mW/cm2 calculated at the lamp aperture, 1 min UVC irradiation time reduced bacterial colony forming units (CFUs) by 99.1% on agar.", so a 30W is 30,000mW depends on the mW/cm2 over the area of the water (internal volume and time in the tube depending on flow rate). So a longer tube = longer radiance time of the water for the same flow rate, or double the length to double the flow rate (assuming wattage is over the required).
So given the bulb is shorter - this makes sense that the maximum flow rate to be effective is less.

Reducing the flow rate by splitting in two, then applying enough UV for that flow rate is valid.. just make more bulbs and connections but less horizontal space.

I see the output rising only a couple of feet above water level, so the pump will be pumping at its most efficient rate.

Feeding the plants.
Currently I have a small pool at the top of the waterfall - this is about 1 foot deep and holds a number of plants that have nitrogen fixing (ie removes nitrates) roots. I'd like to keep this idea as it works really well. It doesn't have to have all the water going through it, but I could split some directly over the water fall, then have a "stream" that is a long tough that holds lots of plants that then empties close to the water level.
I need to read up more in how I can do this in full sun for the new pond, given my existing veggie filter is in the shade. It won't bung up easily as the majority of the water will pass over the falls or with little soil (may use planting foam) the roots will be exposed anyway.

The output I'm thinking will be slow so it could be situated simply to pipe back into the pond.

I also want to have lilies in the pond, the issue here is that they should be on the opposite side of the waterfall but in sunlight - to essentially use the leaves as sun block to reduce algae on that side of the pond that receives the most sun.

 

[easyrider]

^^^^^^^^^^^^Epic ^^^^^^^^^^^^

 

[NickK]

^^^^^^^^^^^^Epic ^^^^^^^^^^^^

been looking at designing my own UV clarifier - given the flow rates and not wanting a 1.5” restriction..

all about probability of killing the algae cell/bacteria.

pond design and ensuring a high probability that every bit of water etc goes through the filter & UVC. So I’m sorely tempted to make a OpenFOAM model of the pond ao I can see the movement of water..

even looked at the lamps - 262nm deep UV light is required, fused silica rather than quartz blocks less UV and the UV bulbs are very inefficient in terms of UV energy output and the power is spread over wavelengths outside of the most effective killing wavelengths. UV LEDs at 252nm are very inefficient too, lasers give 150mW but need 500W for example.

Even looked if there was a way of an opposite of spontaneous parametric down conversion used in quantum optics - alas no easy lunch on that (using more efficient higher wavelength then compressing to give 262nm). For a more efficient bulb.

Thinking of a small filter chamber on the end with an amalgam 40W which seems to be the best UVC bulb in terms of efficiency (in wave length and in conversion vs price).
Then using baffles and weirs to increase dwell time vs flow rate - hence EA for 2” pipe using two 55W UVC with a U bend between them.. essentially 2 meters of UV exposure!

 

[NickK]

So the drum an bio tank should be arriving tomorrow but the pipework, pump, bio media etc are stuck I believe for a week due to covid19 shutting the wholesaler..

let’s see..

 

[easyrider]

So the drum an bio tank should be arriving tomorrow but the pipework, pump, bio media etc are stuck I believe for a week due to covid19 shutting the wholesaler..

let’s see..

Pics needed.

I have been planting some Cuckoo Flower, Lythrum salicaria, and myosotis palustris

 

[NickK]

Pics needed.

I have been planting some Cuckoo Flower, Lythrum salicaria, and myosotis palustris

will do- also been doing my sums with one design 3.7m front x 2.5m sides x 1.6 back and 1.8m depth is about 6800l, however a little longer sides and I may be about to get closer to 7500l.

 

[NickK]

Photo




Ok that's a bit mean...

What's in Box #1?

It's a DracoDrum Solum 16




What's in Box #2?

It's a DracoDrum Bio filter




Ok smart Alec.

Here's the filter for Pond 2.0. The drum filter sits on blocks to bunk it up if you were wondering.



4" inlets and outlets all the way through too Total length is 1.2m long Big Boyz Toyz!

Unfortunately the second delivery has got caught up in Covid19.. so I'm waiting on the pump, pipework, and media..

 

[NickK]

First test - can't do anything else until the rest of the stuff arrives but... video time

 

[NickK]

Output of the old pond pressure filter (the clean water being returned to the pond) used as input into the new filter as a test. Left for about 25mins until the system initiated a clean by itself then collected the wash waste to see what came out.
The jets are low pressure due to the garden tap being only cracked open. In normal ops it'll need a little more pressure so the spray is wide enough to cover the entire drum (if I open the tap full I get a good 3+ bar).

I may stir up the dirt and simply pump it through the new filter tomorrow

 

[NickK]

Installed the new filter in the old pond, rerouted the pump, put the old bio media in the new bio chamber - the old system wasn’t doing a good job.

The pond looked like a mud pond after that! The new filter has been cycling washes like crazy. Large bucketloads of crap down the drain.

could have points on the filter. First is the spray noise, this is a balance/trade off with how clean the drum is after a wash. second is when the system is running with a seriously dirty pond, it’s better to run the drum to have the drum wash a couple of times for the cycle. However at the start it’s washing each minute.