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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 













Bunnings Team Member
Bunnings Team Member

Re: How to refresh my fish pond?

Hello @Thierry


It's good to see your frog pond display working. Using rainwater is ok, but it does mix in with all the pollutants that have settled on your roof. It becomes even more toxic if your roof has been sealed with a solvent-based waterproofing agent. I would probably stay with tap water because you can disinfect it and leave it out in the sun to reduce the chlorine content.


I find it easier to install a Solar Magic 100/300lm Hi/Low LED Spotlight on the surface because there are no wires to worry about and works throughout the night and charges in the daytime. Plus you can have several of them surrounding the entire pond. 


If you need further assistance, please let us know.




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Re: How to refresh my fish pond?

Hi @Thierry  and @EricL  FYI

Hay Your frog looks great working. Good use  of the black pipe i dosnt  matter if it leaks as long as its in the pond you might find good bacteria will grow into the leaks and close them up over time.  Eric was right that pipe must have being 13mm not 19mm. 


Underwater pond lights are  nice but even the best of them can corrode or seals fail eventually ( 5 plus years)as rubber seals harden plus they need monthly cleaning as nateral good bacteria grows on them. and it may not light your frog up much on pool edge.  So a  good pool edge  solar light beaming  onto your frog will look quite  good.  Your fountain light is extra good as the light is placed directly under the water feature lighting water sprays worth the cleaning efforts required. I try light  up water from above with narrow beam  spotlights rather than in the water is my choice. it works ok


@Thierry  if you wish to store  tank water  you can use it for garden and fish tank but I would not install one just for your Garden pond  as  you need to  enjoy your  pond with as less troubles as possible.


If you need to add 500L to your pond buy a childrens blow up  wading pool around  200- 500 L  and let chlorine evaporate for 5 days and it will save you  chemical  costs (pond chlorine neutralizer). Store kids pool deflated for later use. This will give you clean chemical free  water with zero parasites .


Tank water Vs  tap water

Tank water

I think it is  sensible to rule out heavy metals  and polutents from rain water in most parts of  Australia  as for fish tanks I am calling that a non issue as I use a log book to record direct test results via DIY test kits.  I collect 5000L rain water tank via a first flush  roof system and I use a log book testing all water  for every heavy metal and what ever I can is the main risk in a city taken from bottom sludge. I also do a microscopic parisite count to make sure populations are not out of control . I am planning a  water filter in future   to  ensure clean  water.  Zero registerable concentrations recorded in sludge 2 or 3 years buildup.  Crop areas may get pesticides but people drink  roof rain water  out in the country, and bore water and river water we all do to (Murry river alge blooms they where drinking that.  City  Dams also collect rain water and will be tainted by poor air quality.   Just look to your health of local streams the ultimate test  of  air pollution is  the fish healthy  and  alive?  We humans are breathing the exact same  pollutants on a daily basis and arnt hitting the panic button or should we.



The biggest significant factor with rain water is it is usually of a low pH than  pond water so that has to be balanced before adding it to pond. A rapid pH change will effect fish  super fast and do far worse harm. Leaping/flashing fish  etc Fish can adapt to pH changes  but require 24 hours per pH point change as a guide, same for other water change factors.  Know  one thinks about the water  temperature change  either as this can trigger a pH crash.  You ever jumped into cold water well fish  cant get out and get warm.


A Koi fish  can live over  100 years in a perfect environment. That  gave me a whole new perspective on Koi as pets. But most kept Koi live an average  of 25 years for many  reasons.


Tap  water with chlorine

Chlorine in tap water will kill  and or greatly diminish  you bio good bacteria in your fish tank and filter that is why they add it to  drinking water to kill bacteria  good or bad in our drinking water supply.  @Thierry  May in the future need to do a 1/3 water change in the pond  for many reasons thats 500L so the only real solution  is to add 500l  chlorine water gradually over a week  with  fish pond chlorine neutralizer this can be done quicker.  Dont forget what is his pond pH vs  tap  water pH differential as that is every bit as deadly too fish. Gold fish are more tolerant than koi in my expereance. Gold fish only live 3 to 5 years too. To  add 500L tap water to a  fish  pond consider buying a inflatable wading pool adding 500L tap water to it let it self declorinate for 5 days should  do it as @EricL  suggested will also should start to match pond water temperature All that  left is  water pH differential this requires a  water test ki or add water 100L per day as an  Ideal.  But gold fish usually survive  many  events so we  learn the ideal and try best to match  that as  resources  allow.


Rain Water is far  less deadly than direct tap water.  But watch  any pH  and temperature changes that is  why I advise @Thierry  and any  backyard pond  owner  to add tap or rain water often as Smaller percentage amounts wont alter temperature or pH levels or add lethal doses of chlorine out of their fishes and ponds safe range.  Chlorinated water will be diluted  to a smaller percentage not ideal.  


Best all round solution with limited  resources

De-chlorinated tap water  Via kids temporary  pond 5 day  de-chlorination method is a very good  clean source of water for  fish owners. Temperture balanced for most part. Clean water source. No harm full chlorine. (pH differential is unknown quantity add slowly 200 L per day. Ideally 1500 litre tank.)



Re: How to refresh my fish pond?

Hi @Jewelleryrescue and @EricL 


Hope you had a great new year.


Just an update, I think the UV bulb has blown up and its its only on a couple of usage. I have been told by the shop, since this is a replaceable item, its not covered under warranty and need to buy a new globe. Very upset about this.



  the LED light also is playing up with on and off.


I will bring it to the shop.

Re: How to refresh my fish pond?

Hi @Thierry 


Not so happy new year for your pond.  How  are you sure it is blown as  they not like  regular bulbs you can see them on except via a viewing port.

I believe you though.  Keep in mind the fault maybe the terminals to the globe that means a  genuine warranty claim


I certainly  would expect good  UV Bulbs from a decent UK company Bladgon.    But failures can occur sadly and I would  also be as  disappointed like yourself.  As  far as warranty goes  they state 3 year warranty they dont openly show warrantee document.  I would say in regards to consumables they should  be expected to run for more than a month and if it fails too soon I think the company blagdons in UK would spare a $21 bulb just to preserve there reputation.

Also you remember  you asked  us about an led light  flickering at you on purchase maybe it was  the viewing port to the UV light you where seeing .That  means it was faulty from day one which  means they should replace the bulb for free.


I would also  definatly contact blagldon in the UK and see if they are willing to have a poor reputation over a 21$ part.  Get your reciept ready.


I recently also experianced a product failure only 4 monthes in but  in contacting the supplier they talked me through fault finding it saving a warrantee claim and paper work all round.  I had a win you  can too, talk to Blaglon UK and see what they have to say.


The part in Australia  is $20.90 at the aquarium shop Thank good ness as some UV bulb are  $100+


Please keep in touch with your progress     This can happen with any brand more so the cheaper nasty stuff which blagdon is not.


Re: How to refresh my fish pond?

Hi @Jewelleryrescue 

Hope you're well. I spent the whole holiday period 2-3 weeks in isolation due to covid.


Yes, I believe the UV light stop working as I cant see any light on from the cover.


The retailer said if its bulb burnt out, need to buy a new one, unless its a faulty unit. That's why I bought it from a shop, and I will bring it to check tomorrow.


Meanwhile I will email the  Bradgon  uk about the issue.




Re: How to refresh my fish pond?


Sound like you needed a  Uv for your house to re covid . I hope it was not to bad a covid  for you, but 2 to 3 weeks sorry it sounds like it was tough.


I would take the unit to your dealer or did you buy online.  


Important put your foam filter sponges and ceramic bags  in the pond as there you bio filter  bacteria and need to stay alive just take main unit.


Show the old bulb  not working bulb in the unit and try a new bulb in unit if new bulb not working then is  the unit at fault and a  warranty claim 100%.


Yes talk to blagdon as  its their baby and I am sure they will want the dealer to treat you right they may give you help  and give the dealer help to help you faster. If  need  be tell them this is an item of converstion in a big forum  and  many people following your blagdon story.  Think  as positive as  you can.


Was that your flickering LED  we  talked about last year?


Re: How to refresh my fish pond?

Hi @Jewelleryrescue 

My whole family got covid , one after another, so had to stay isolated during new year. Mine was mild.


 Bought it from a dealer shop just in case need warranty claim.

Now the shop is staying the globe has 1 month warranty, and will be due soon.


Yes, the LED LIGHT flickering a few times from start. 


FYI, few times, the fountain got blocked due to accumulated algae, so i rinsed the filter (does that mean the good bacterias also gone?) and back to normal flow. 


One baby fish died too few days ago , maybe got suffocated by algae.


Yes good idea - i already email Bladgon about my disappointment, but will mention the public forum too






Re: How to refresh my fish pond?

I am sure that globe  well inside the month warranty ?  


No 1 rule is water quality is good s o we need pump and UV 100% operational.

My Main concern is the unit is making  good contact with the  UV tube re the on off flickering is now suggesting a bad contact or other fault that came with unit from day one. Install a new bulb and look at that UV port.  And further proof is future alge erradication is not working ,  The existing  string alge needs to be maunually removed and you cleaned you filter and that needed to be done so all is good.  The benificial bacteria will have being reduced from foams etc  but your pond is big enough to have bacteria growing on the edges to support life. 


You  should see faint blue light from UV viewing window with filter foams and cartrigde removed


It takes 2 to 3 weeks to regrow bacteria .  Question dose you water smell  distinctly bad?  from standing near it?  if  yes we can  buy some bacteria kick starter if need be. 

Many reasons  for a fish  death alge isnt directly one of them so we good there.  


Are the other fish jumping out of water and doing weird things out of the ordinary?  Did the dead fish look healthy? no cotton wool on it etc.  Was  there red  streaks on skin a sign of ammonia, nitrite stress?  Other fish look healthy?

Please take photos of any dead fish both sides and bottom in future I will try help


If your pond  grew alge it is  proof  the UV wasnt working at all during all that time.  So ask  shop guy why a 1500 litre pond can grow  alge if UV working. Answer is if everything flowing right and UV on  it could not.  I read the blagdon 6000 3year warranty  Lamp  no warranty but you said unit flickering from day 1 so that is different called DEAD ON ARRIVAL it should be working 100% Plus CLEARWATER  GUARANTEE states that for 1 year after purchse your water will be clear  to a depth of 1 meter With T&Cs  your alge fails that test.


Well they said they will replace bulb so thats a start now we just need to make sure that flickering  UV isnt happening like when you first bought it.


You making progress keep it up.


Re: How to refresh my fish pond?

Hi @Jewelleryrescue 


Hope you're well. And no I haven't forgotten to reply.


I have been waiting for a response and me being busy. Today, i dropped the pump to the shop which will then send the item to the distributor interestate to test for 7 days (leaving it on) if the LED light flicker. If it doesn't the same pump will be returned back .


As for the uv light, the shop has obtained a replacement globe and is a one off only. The retailer said usually, if theres a power outage, this may occur. So usually no warranty.


Will be receiving the pump in around 2weeks time.


Btw, a new fish died recently, i think it was the injured one , which got the tail stuck in the plant 2-3 weeks before it died.




Re: How to refresh my fish pond?

HI @Thierry 


I am pleased Blagon taking  us seriously and testing your unit,  I hope they find the fault is repeatable and fix it  as a honourable company. AS you unit was flickering from day one , The flickering is  the same as a multiple power outages the on off on off on etc  is the same as power outages.  So if they are right your fault in the unit caused bulb failure but it sounds like they fixing it so great news.


Sorry about your fish death I never heard of a fish getting stuck before ummmm Unless the fish was trying to scrape of excess parasites between the weeds.  Its  like us if we have a moquito bite on  our back we scratch it on a door post etc if  we can t reach it fish do the same on the bottom or objects or pond walls.


Hay  @Thierry  if you want to try covering all your fish health issues in general  if other fish doing some unusual activities Can I recommend a general fish tank medication.  AQUA ONE is the brand. Broard Spectrum Remedy for  your 1500 L tank = 75mL. First drain 1/3 of of your tank water and take out any debris or dirt /leaves in the tank replentish tap water as the clorine is also  designed to kill parisites in water. I would add a second dose 3 days later of Broard spectrum  remedy (with out a  2nd water change.) This will alter your water colour green for a while do not be concerned by this as it is the colour or malachite green  active ingrediant.  Also  after using the aqua one i find the lid leaks so I put some cling film as a sealer to help stop this leak. Add  Cling film to stop  leak after openingAdd Cling film to stop leak after opening


AS an additional fish tonic add 3 Kg of Non iodised salt (supermarket)  to your tank 1.5 kg per day for 2 days then stop salt is it can build up use a bucket of water and mix salt until its disolved fully .  Remember  salt can build up in a tank but is reduced  with water changes. The salt helps builds nateral slime coat to the fish which in turn helps repel parisites, This  will give you approximatly 0.2% salt level  the max is 0.6% as a guide.


These 2 actions will help  protect  your fish  make there days a little better and there is a good margin of saftey as not to over dose. But try limit these treatments to every 6 monthes at need or annualy  mid summer as a general pond fish medical.


It is great you have no  gravel in the bottom as this recuces medication efficency with extra trapped organic load  hence the water changes too.


Great to here from you we will support yo though this journey.




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