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How to refresh my fish pond?

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How to refresh my fish pond?

Hi Team


I have an outdoor covered fish pond facing North east, capacity 1500 L.


Could you please advise:

1. A water pump, filter, uv light (all integrated ?) 

2. 3 pond lights?

3. Do i need to remove the middle  pot and install a new pump there? 

4. Im thinking if can fit through central pot water feature


My current pump with small integrated filter (after 2 years) is not pumping water although everything appears to be working. And it was connected to an external UV. Also, my 3 led lights are weakening now, need replacement. 


Need to fix this asap as theres 8 goldfish 













Re: How to refresh my fish pond?

Hi @Thierry 

Yes  3000L - 5000L per hour for all components to keep things  straight forward and larger filter minimises maintinance periods too.


The 5000L  rating for  pond stuff is for no fish, just water.   Fish load down the filter with OASE  5000 Pump-UVC-Filter 3in 1 this will support  fish  in 2500L tank. your pond will be very clean and healthy for the most part and need a little less attention.  And  yes included fountain. 


The 3000L rating for Bunnings Aquapro AP3100DW(this is 3000L per hour  Pump i/n 2810303 and the  Aquapro AP5000UV Combo Pressure Filter I/N 2810202 will support your 1500 litre fish  pond.  and yes it  will still support a fountain in the middle and waterfall at the side if you wish you will have to buy a fountain and base for it separatly best to  have  water  pipe coming out the side of filter and  spraying horizontal it still looks and sounds good it can be a simple tube. No water  lights included.

You can add a tee piece  and divert water to a water fall feature you just need some more  tubing People in store at bunnings  can help you with extra  components and make sure it all fits  together.


Buy lights separately as you wish for. A water fall is just a  dish shape with a hose water inlet at the back or same for  a   fish ornament that spouts water out its mouth . Many personal choices here easyest is in store service in plumbing section.  Below pic is a  sample  of your possible system.pondeg.jpg






Re: How to refresh my fish pond?

Hi @Thierry 


Ok lets help your fish it is not good two are  dead so lets try make them  more comfortable.  


Your tank size is 1500L  we will add some salt to the  water is a controlled  manner to follow.

Salt acts  like a soothing tonic to fish and it helps them generate a slime coating to repel parisites.

Salt should not be used all the time as it will lose effectiveness and may accumulate increasing saltiness.  We  can not exceed 6 parts  per million.(PPM)

Salt will help diminish parasite  populations and bacteria in water.

Rocks breed anaerobic parasites that fish touch  while swimming so its great you dont have them.


Salt non ionized regular  table salt in packets from supermarket is good (can also use plain pool salt) 


The most important thing is to not change water parameters to fast as fish will suffer .


What to do to help  your fish with a health tonic


Instructions  in a bucket of  collected  pond  water mix  450gm salt in bucket until dissolved fully each day for 5 days

This  will raise your  estimated pond salt levels to 5 ppm With a safety margin incase pond is plus minus 500L.

Stop add no more

Salt will diminish slowly  over time  with any water changes


Sick Fish 

If any fish  look or act unusual put  one table spoon  salt in one bucket of pond water and  put the fish in the buckets for 10 mins watch them. If they become distressed or start swim funny return  them pond asap.  They  should vomit up helping  reduce internal gut parisites if they present.


Visually Sick Fish  if you wish put them in a shallow bowl glass container and take  photos of there  conditions both sides fish and top I might be able too help more. Red sores, missing scales white scales and white fluff, bloated bodies etc.


Kind of a Big Deal

Re: How to refresh my fish pond?

Hi @Thierry 

I should  tell you  i like the use of your space and the pond looks good :smile: 

I was thinking too much about  pond pump stuff  problem to appreciate your space here and say so. Nice space.


I re read you initial post  you have 8 gold fish that not a lot. (I did a  quick  count of your fish in picture and doubled it roughly for  2nd half of the unseen under water in  pond and as you said they breed so more fish may come. If you use recommended pond filter options  30 goldfish will be comfortable in 1500 L. 

So my estimate was for more fish  which  dosnt change any pump  information for 8 fish as the more  water a filter system can handle the better  water quality.   If some one double filtered your drinking water thats great but under filtering it is yuck says your fish. 


Fish  farmers  have 1000s of  fish in  small ponds but they have super filters and constanly monitoring there fish  health because  within hours mass deaths can occur and loose of profit.


You can drill  your pot base  with  care  and have a fountain tube in the middle spouting.  You can lift your pot and put pavers underneath to allow water pipe access with out squashing it you  can  use a 3in 1 system and take the water outlet and divert it to  your pot water  spout or a  cascade on the side too.


You  mentioned a lack of growth and  you feed them once a week I might increase that to one  medium pinch of food every two days  as a guide if this is possible for you or  every time you visit them and  feel like feeding  them.

Once a week is ok the fish will scavenge and eat mosquito  larve and other water bugs and even  nibble on the growth on the pond hoses ( look for clean nibble patches on your hoses)  as food. But they will definaly eat the smaller babies (that is nature and stops over population in your pond, a 10mm mesh made into a under water box will be a safe spot for baby fish) only the strongest will survive if they  really hungry they will pick on adult fish and kill them reduce competition for food I am estimating as they dont always  eat them.


It is a great  bonus nice work  your pond under cover  this will reduce  alge growth and  rain water changes pH. Later if you wish to lean more buy a  water test kit  and learn what  the results mean but I also understand you just  want some fish and not want to know the history of water . I had that level of knowledge too at one point but my koi demanded I learn more to live longer.   


Feel   free to ask me to clarify anything i  failed to explain properly.



Re: How to refresh my fish pond?

Hi again @Jewelleryrescue 

Thanks for your response and for sharing your fish tank - looks fantastic!

To summarise the case of my pond, I have 8 fish and pond is facing east, and but is under cover.


I still get algae issue but UV light should fix it.


I like the idea in your previous photo of the Blagdon inpond 5 in 1.


Also, the pot is sitting on 2 bricks and rocks surrounding it. Theres already a small hole (should be ok if only power cord will go through it)


I will check if the pump can fit inside the pot together with a fountain + LED light, and if possible to have a cheap frog water feature linked to it, from flow control.

1. Should i get a blagdon 5 in 1 3000 Or 6000? As from what i read the 3000 should be enough? Will UV light 5kw on 3000 enough?


Thanks Thierry


Re: How to refresh my fish pond?



Hi @Thierry 


If you wish to use  blagdon 5 in 1  the  6000 will properly support you fish now and into the future with its larger capacity and it has that led light too and enough capacity to run a side water feature later. 3000 may just work if you clean it regularly but not enough water pressure  for side feature.


Can I suggest the fountain Blagdon  go into the middle of  pond stand alone no pot surrounding it (as blocking/limiting  water flow  will hinder water cleaning function around the pond Also if in the pot pump return water must enter small base hole of  the pot  half blocked by the  cord and it is possible  to get dead spots in your outer pond alge spots etc. Water  through  the pot hole wont be big enough  to replace pumped out water in pot pump could run dry.


Now you around your middle  feature fountain you  can add  two pots either side, or  4 pots in a square around  but away from filter with the fish swimming under the 4  plants it will give them a more interesting happier  environment or design your new  pot layouts.

Re: How to refresh my fish pond?

Hi @Thierry


My apologies for not seeing this pump on offer. In reference to the AQUAPRO 2000 All-In-One Pump And UVC Filter System, it should work with the size of your pond. Have you considered making an independent filter for the entire pond? It is mainly made of an Award 50L Black Storage Container with Lid and Wheels, Ki-Carma 20kg 10-20mm Drainage Gravel, 3M Scotch-Brite 120mm x 80mm Heavy Duty Scrub Sponges, QEP Tile Sponge and Everhard 600mm x 6m Drain Matting.


The basic assembly involves cutting a hole at the bottom to let the water out. You can place a hose or a pipe fitting of your choice for the outlet. The rocks go to the bottom then the scrub sponges next followed by the QEP tile sponge. The top part is occupied by the drain matting. The outlet of the pump is run through the top of the giant filter. In essence, it is like a giant freshwater aquarium filter only on a much larger scale. 


Done properly you'll be able to propagate the nitrate-eating bacteria that will keep your pond fresh and clean. It will provide you with long-term filtering and you won't have to keep cleaning it compared to a small filter. In combination with the salt regimen that @Jewelleryrescue suggested your tank will be very clean and free of algae.


If you need further assistance, please let us know.



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Re: How to refresh my fish pond?

Hi  @EricL  and @Thierry 

 Bio balls vs   rocks.


I totally respect EricL advice  as it is the mainstream solution here but I do  believe this area is  evolving as to better solutions for tomorrow.


 I think you will  like to  grow with my journey down this rabbit hole as I am building a  mega filter trying to keep this real. See if you agree ?   The rock solution is ok  but  there is new evidence of a better way of building a self cleaning bio tank as I am in the middle of that project now. When I finish  my design pros and cons I will share  the design into the future after I test proto type and tweak  final  design.


Rocks specifically (volcanic perforated )add more surface area to grow  bacteria on an inside if they porous that is 100% true. But they are heavy and clog up over time and water flows around them not through them. Clogged rocks invite parasites to breed in an on them.  So its a  pain to clean them and once bacteria  colonises rock surface it slows down growing. To  clean you have to dig them all out wash them (heavy work) even in pond water killing bacteria is un avoidable and waiting for a  colony restart can be a month.  (there are some great colony restart additives that do work in 3 days)

Key point is there are 2 bacteria types one is  aerobic the other Anaerobic in a rock system anaerobic bacteria  hide deeper into the rock pores away form any oxygen.  Please discuss with me if  I get any facts wrong I need to learn too so I  dont built a white elephant.


New  Filter  concept  (actual proto type design still being finalised so bear with me  at concept level)

Anaerobic Bacteria Tank

Its being proven the that bacteria eats the ammonia and Nitrate mostly as its growing! as food. So think Tank no1 The pond water  can be dumped into a settling tank with bio balls buffeted by incoming fish poop and water.   The  water movement with minimal pond air as  pond intake is in the bottom of the tank anaerobic water. The incoming water movement keeps  the bio balls  clean and no home to parasites as well as knocking of the  old anaerobic bacteria enabling regrowth for maximum self cleaning  and bio filtration. The poop settles towards the bottom with the the old bacteria and is flushed out periodically on to  grateful garden plants via a   floor drain  valve.

What is a "bio ball".... well its a man made  plastic ball various designs that are hollow to allow maximum surface area for  bacteria to  grow on inside it and out.. The  same bacteria grows on all surfaces in your pond feeding on fish wastes.  If it grows on pond walls why do we need  more well thats  because we are stocking the pond with more fish  that a nateral pool of water can provide and we need  larger colonies of bacteria.  


Aerobic Bacteria Tank.

So think bio plastic balls floating in a 2nd  tank  not overly congested you want bioballs to move with a  steady stream of bubbles underneath as one of the bacteria types is aerobic (needs oxygen) .  

What happens is the bioballs are constantly bouncing around each other and knocking of bits of old bacteria which is perfect as its only the new bacteria growing is doing most of the  converting. So the old  bacteria falls to the bottom of the tank dead as waste and  if you install a floor drain  simply open valve into your garden it will suck out the bottom mess in a jiffy  and plants love it.

Key  features are

  • constant self cleaning (rocks  cant do this)
  • no build up of old bacteria  (rocks add to this problem)
  • No or minimal parasite breeding ground  ( Sediment clogged rocks parasites  can thrive)
  • maximum  bio filtration with constant young growth  ( old growth bacteria reduces bio filtration.)
  • Easy to purge  waste.  (rocks are labour intensive at all  levels install and clean)

Pumic volcanic rock floats and  may work instead of bioballs  but over time will smash its self to sand.


Well thats the future it will take a few  years for those facts to become mainstream but you heard it hear first.






Re: How to refresh my fish pond?

Hi @Jewelleryrescue


Thank you for the insight on other possible filters. It's definitely something worth considering, I suppose it depends on how big the filter tanks will be. I reckon the third filter tank would be a biological filter such as a floating raft with plants in it. When the nitrate enters the water the plants absorb it and clean the water at the same time. But your idea of flushing the solids into the garden is great as this will be like a natural fertilizer for the garden.




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Re: How to refresh my fish pond?

 Well @EricL  your very close here re plants getting involved.


If you make the plants  with no soil ( as soil is a nice little hidy place  for water  micro organisims to breed in). Basically treat them as hydroponic  just use floating raft with bare roots but I cant vouch for that is a real solution definatly out of my skill set.


When  it comes to hydroponics I really a I have no idea in that last  plant stage of the  nitrogen cycle. That's  a lot of more study in itself.


FYI  in a man made koi pond plants shouldn't be in the water but around the edges in the  garden to once again to keep  dirt out.   The larger the pond the less it is vulnerable to  dramatic and sudden pond water changes and or pH swings if sudden influx of rain  water etc   


I remember knowing zero about fish but i still  enjoyed keeping  them and made tanks for them yes  my fish lived an died and had strange conditions so I learnt more to save more fish.  But  it is important not to bog regular fish owners down too much just  guide them and help them and fish to be a little happier so if you see me not telling a fish owner something  its to strike a balanced  solution. Thierry  wants to put pump in  pot plant I had to suggested no as the pump simply wont work  well.


Trivia : Did you know Koi fish in perfect conditions  can live 100+ years?  lol puts alot of other pets to shame re life cycles  but in realitiy they live an average of 23 years as there owner may pass away  and pond gets neglected is one scenario they get shorter life spans.


Re: How to refresh my fish pond?

Hi @Jewelleryrescue and @EricL 


Thanks for keeping the ball rolling.


@Jewelleryrescue  i like the idea of the Bragdon 5 in 1 6000, which i will like to give a crack. Its a cheaper option and an easy installation. I think its the only one model in the market.


As advised, will remove the middle pot.



1. The bragdon 5 in1 6000 pump says max flow per hour is 1500. Is that sufficient for my pond?


2. The 4 plants with pots- whats plants do you reckon i should get? 


Not sure about the quantity of the filters etc, and other ongoing costs such as filters replacement but if once a year to clean im happy with that.





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