Should I do an Annual Pond Clean-out?
Just got this question today:
Customer John K’s Question:
I am sorry to keep bothering you but I am new to having a pond. On your website you recommend California wetscapes and their checklist says they remove the fish which we have already done. Then they pump all the water out of the pond, pressure spray the pond clean and then refill it. Would you recommend this? My pond was new last year, it has a few plants and got some mulch in it from the landscaping around it during the winter. Now it has been running for a few days in 40 – 50 degree weather and it has foam all over it. It is about a 4000 gallon pond. I have no problem draining and refilling it and would not mind pressure spraying it out, but I do not want to do this if it is not necessary.
PondMeister Answer:
I hope your landscapers did not use any fertilizers or poisons around the yard where the pond is. The slightest leaching can wreak havoc with the pond. If you need to fertilize anything back there, use pond water – it’s the best fertilizer EVER.
I am a big fan of annual clean-outs. All the debris that settles at the bottom is a haven for algae and other bad things. Best to start over. Make sure you de-chlorinate the water before you put the fish back in. Try to retain as much of the old water as possible. The guy who does my 6,000 gallon pond each year has 3 – 1,000 gallon temporary tanks so we can keep a large portion of the water and not stress the fish too much.
Below is Aquascape’s Official Instructions to their Contractor’s for Pond Clean-outs
Spring clean outs are usually done early spring, before your pond awakens from it’s winter dormancy. Clean outs should take place before water reaches 55°F.
Things you’ll need:
- Container to hold fish and frogs
- Fish net
- Five gallon buckets to collect leaves and debris
- Old clothes (You’re going to get dirty)
- Gloves
- 25’ of 1.5” or 2” discharge piping
- Sump pump with a screen or skimmer pump with chicken wire around it
- High pressure nozzle for your garden hose or power washer
- Garden shears (for trimming plants)
Steps for successful clean out:
- Begin draining pond. Use your pump with chicken wire or screen around it to help protect fish from being sucked in. Use some of this water for the container to house fish in. Also make sure you move the piping around a few times so all the water doesn’t go in one place. (This water is excellent for fertilizing plants.)
- When water level reaches about six inches, turn pump off and catch fish. (It’s a waste of time to try and catch then when pond is full!) Place fish in container and make sure to cover if you have Koi because they do jump.
- Once fish and others are in container, begin hosing down rocks and gravel.
- A high-pressured nozzle or power washer should be used for hosing down rocks. Don’t wash away all algae because a little bit will be beneficial in developing your ecosystem. (For an average size pond, 11’x16’, this takes about 15 minutes.)
- Take this opportunity to trim back any plants that appear to be overgrown.
- The most time consuming part will be washing the debris off your rocks and gravel. DO NOT use the power washer for this; use the water coming out of the garden hose. Keep pump plugged in, water and sediment will go to the deepest part of the pond so it will be able to get sucked out.
- Clean out skimmer box by sucking out water and hosing down. Clean out net and filter pad too.
- Clean your BIOFALLS mats and lava rock by hosing them down until they’re clear.
- Now that the pond is pretty much cleaned out, remove the pump and begin filling the pond. Once your pond is half full you can begin to reintroduce your fish and plants.
- Remember…if you’re using city water, you need to use a de-chlorinator such as Pond Detoxifier from Aquascape. Chlorine will kill fish. Add the appropriate amount of de-chlor so you can start adding fish. Dip your buckets into the holding tank and fill them with a few inches of water. Add your fish and float the buckets in the new water.
- After around 15 minutes, begin splashing pond water into the bucket. By now temperatures should be close to the same (pond water and bucket water). You can now add fish into pond.
- It’s very important at this point to add Beneficial Bacteria to “jump-start” the ecosystem in the pond. If the WATER temperature is between 45 and 55 degrees, use Cold Water Beneficial Bacteria from Aquascape and if the water temperature has already warmed up over 55 degrees, use either Beneficial Bacteria for Ponds – Dry or Beneficial Bacteria for Ponds – Liquid.
Note: Clean out should be done in timely fashion. Fish are weak in the spring. They shouldn’t be kept in full sunlight or in container outside of pond for more than a few hours.


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Right about doing an annual clean out. Good for the pond plants and fish. Good point about not stressing the fish.
April 12th, 2011 at 2:44 amA couple of years ago I purchased a pond vacuum. I use the pond vacuum to clean and drain the pond at the same time. The attachments on the pond vac allow me to get down into the gravel and pull the muck that has accumulated there. I don’t pull all the muck out from the bottom. I plant my pond plants directly into the gravel in my pond. I find that my pond lilies are much happier and healthier. I find that the fish are less stressed by not being moved out of the pond and I have found that the pond ecosystem recovers really quickly. I start at the highest level in the pond and work my way down to the lowest areas. I have also found that cleaning the gravel in the fall with the pond vac also helps to keep the pond cleaner in the winter months. I have had several large (6000+ gallons) over the years and this has worked well for me and my pond inhabitants.
April 19th, 2011 at 4:53 amI agree! Great input
April 20th, 2011 at 10:50 pmI agree! Since I bought and use my pond vac several times a season I have almost eliminated having to do a compleate drain. And it’s wonderful for keeping the muck out of my bio filter.
April 21st, 2011 at 7:48 amI live on Long Island and for the last five years I have pumped it out.I pull a lot of debris,leaves from the bottom.I was taught this from day one.I rinse the biofall mats,skimmer mats,Reintroduce my cannas and other tropical plants.The pond always responds with the best it can be.My problem is that all my rertailers are closing down.I have an Aquascape system,and I cant even get any info from “the pond guys”.They stopped publishing the magazine around 2 years ago,and the website is useless now.Does anyone trust them anymore?I swore by them,the system kept my pond beautiful.But now I cant get a simple answer from anywhere.I will figure it out,but they could’ve made it easier for me.I cant even find the products that I am used to.Backstabbers
April 22nd, 2011 at 1:01 amSorry to hear that you were having problems with your old pond contractors. We carry all of the Aquascape products and will ship directly to you from our New York warehouse and no tax for New York!
April 22nd, 2011 at 12:42 pmHmmm all good points. I recently got into some issues with parasites. I ended up treating the pond and the Koi are all ok. My pond guy actually told me that I can leave the Koi in if even I do a 50% drain. It seems like he was right. The fish stayed calm and i was able to de-chlorinate the pond while it was filling up. The issue I have is my pond plants especially my lillies are not spreading out. They bunch up in one spot which does nothing when the sun is out. Not sure what to do. I like the idea of putting them in stone or between the boulders but not sure if they will grow or not.
July 26th, 2011 at 8:27 amThank you for the wonderful and insightful information. However, I am experiencing a challenge with the waterlillies in my Koi Pond they are not growing and or spreading out . A bit confused as to what to do can you please provide some suggestions.
October 21st, 2011 at 8:05 amYipes…I am probably not the one to ask. My 24 – 12 year old 2 foot koi have had there way with almost every lily I have put in my pond. The only success I have had is with a well-established hardy lily I got at a local nursery. From what I have read you must bury the plant with the crown protruding and cover the top layer with stones to prevent the koi from rooting them out…
October 26th, 2011 at 11:43 pmI installed an IonGen in Aug. 2011. It killed all the algae and cleared up the water. Now I have rust color dead algae on the rocks. What is the best way to clean? Do I have to drain pond and power wash. The pond is 8000 gallans.
I live near Wasco IL. Does Auquascape clean ponds?
January 27th, 2012 at 6:52 pmTry using a stiff Wire Brush. I have forwarded this over to Aquascape HQ in St Charles, IL to see who they have locally to help you. I am a firm believer in annual Pond Clean-outs. My Pond Guy has 3 portable 1000 gallon ponds he puts up in a few minutes and he drains the pond and lowers the pond water level to where he can catch the fish. He then puts them in their own water and then continues draining the pond. He just uses a strong hose and it works fine.
January 27th, 2012 at 7:08 pmJust got this back from Aquascape-Chicago:
February 2nd, 2012 at 1:50 pmRichard,
Our construction group can do a clean out. Wasco is right next to Saint Charles. Have him call our construction department, 630-659-2057 and he can schedule a spring cleanout.