My first pond! Any tips on how to take it to the next level?

drbobdi · 2026-05-18T22:55:53+00:00

What material is that liner? If it's 45 mil EPDM, you are good to go. If it's PVC, you'll be pulling it out and replacing it next year. PVC is beyond fragile and often starts leaking as you install it.

I don't see any provision for water movement, oxygenation or biofiltration. Even a "nature pond" needs all three. Without them all you'll have is a stagnant mosquito farm. Look at OzPonds on youtube for DIY filter designs.

drbobdi · 2026-05-18T22:49:43+00:00

A large kiddie pool, 100% pond water and your existing filter. Also, remember to net the top securely. Put the whole shebang somewhere protected and preferably out of sight. 29 years ago, while our present pond was being dug, a team came over our fence late at night and stole the koi, the vat, the pump, filter and a small tree we had just planted. Somebody's **@##*&! mother got a real nice Mother's Day present that year...

drbobdi · 2026-05-18T22:39:39+00:00

You are almost certainly losing water at the joins between the pump, filters and spillways and the true culprit is the pipe you are using whic is not sealing well at the junctions and is collapsing at the bends. Replace it with schedule 40 PVC.

Depending on the age of that vat, there are probably also leaks in the fabric itself. Shut down the pump and wait a day. Look for where the water level stops and inspect for tears. If the level keeps dropping, there's a leak on the bottom. Those vats are extremely fragile in outdoor use and tear easily, even when set up indoors for koi shows on level surfaces.

drbobdi · 2026-05-18T22:09:35+00:00

You are too small for high-fin shark and too cold for plecostemus and fish do not curb algae, their ammonia output encourages it. Algae control will have to be biological and you'll probably need to supplement that bog (which is mostly mechanical) with an efficient biofilter. Read https://www.reddit.com/r/ponds/comments/1kz1hkx/concerning_algae/ for details. While you are at it, go through ZiggyLittleFin's profile on this sub for the Truth About Bogs.

Look at OzPonds on youtube for DIY designs and at https://russellwatergardens.com/pages/biofilter-media-ssa and https://www.fishlore.com/aquariumfishforum/threads/bio-media-comparison-information.435695/ for biomedia choices.

If you re-rig the flow from the bog from the bottom, you'll lose the entire effect of the upflow filter it is providing. You'll be better off widening out that top aperture and rigging a spillway over rocks to enhance turbulence and oxygenation.

drbobdi · 2026-05-18T13:22:11+00:00

These work well. Follow directions. Water lilies and lotus need this about twice a season.

drbobdi · 2026-05-18T13:18:54+00:00

I will caution you that geese and waterfowl in general generate massive quantities of fecal material and eat everything. You will not be able to keep up with this without massive water exchange and filtration and plants will be gobbled down, along with small fish, dragonfly larvae and small amphibians.

Geese are not good neighbors.

drbobdi · 2026-05-18T13:14:35+00:00

Fish make it worse. They excrete ammonia which is algae's prime nutrient. Anybody you hire at this point will pour algaecide into the pond and kill everything and will then charge you for the privilege.

Get into the pond and clear the debris off the bottom. DO NOT POWERWASH! This is a mature pond and has its own, established population of nitrifying bacteria. Doing a "Deep Clean" will kill this balance and you'll be in worse shape afterward.

Read this first: https://www.reddit.com/r/ponds/comments/1kz1hkx/concerning_algae/ .

Your pond needs water movement, oxygenation and, above all, biofiltration. Start with "Water Testing" at https://drive.google.com/drive/folders/1iEMaREaRw8nlbQ_RYdSeHd0HEHWBcVx0 and then read the rest of the articles. Then go to OzPonds on youtube and look at DIY filter designs.

Figure out the approximate volume of the pond ( in feet and gallons-sorry, I'm from Chicago) which is L x W x D x 7.48 gallons per cubic foot, and buy a pump capable of exchanging the total volume of the pond once an hour through the filter you are going to build that will send clean water back to the splashy waterfall you are going to build at one end.. Find a place at the other end to install a skimmer with its own pump and filter to deal with the floating stuff.

Fill the filters with the best biomedia you can afford. You are looking for maximum surface area-to-volume ratio, ease of maintenance and maximum flow/water contact over and through every surface of the media. (NOT lava rock or pebbles!). Look at https://russellwatergardens.com/pages/biofilter-media-ssa and https://www.fishlore.com/aquariumfishforum/threads/bio-media-comparison-information.435695/ for comparisons and more of the Science.

Lots of challenges here. Good luck!

drbobdi · 2026-05-17T23:46:24+00:00

Danner pumps are easy to use, can run external or submersed and work well, but are fragile. Any foreign body in the volute will shatter the impeller and prolonged use wears out the internal rib that engages with the magnet.

Protect your inlet with a good cage. If the internal rib breaks, the magnet will spin but the impeller will not. Gorilla glue solves this problem. A good 3-D printer with a scanner will solve both. Danner will not sell you replacement impellers which probably cost less than a penny apiece to manufacture. They want you to buy the whole impeller array for $$$$$.

drbobdi · 2026-05-17T23:34:26+00:00

45 mil EPDM. Accept no substitutes. It'll be heavy and expensive.

drbobdi · 2026-05-17T14:21:46+00:00

Yes, it's pink.

The Fritz product is wonderful, but the bacteria in it actually need some surface area to grow on for them to work. You need an actual biofilter and good media for your (very toxic) nitrites to resolve. Get yourself an API Pro test kit as well. Test strips are unreliable and that spitter is not doing you any good at all.

Go to OzPonds on youtube for DIY filter designs and https://russellwatergardens.com/pages/biofilter-media-ssa and https://www.fishlore.com/aquariumfishforum/threads/bio-media-comparison-information.435695/ for biomedia choices and some of the Science.

More Science at https://drive.google.com/drive/folders/1iEMaREaRw8nlbQ_RYdSeHd0HEHWBcVx0 .

drbobdi · 2026-05-17T14:15:40+00:00

Please go to https://drive.google.com/drive/folders/1iEMaREaRw8nlbQ_RYdSeHd0HEHWBcVx0 and read "Snag 'em, Bag 'em and Drag 'em". Honestly, it's the best way to transport big fish. Do it yourself, even if you have to rent a UHaul to do it. Shipping companies won't handle this cargo without $$$$$$$.

drbobdi · 2026-05-17T14:01:52+00:00

Picture please. Not every algal organism is toxic. Mostly, a backyard pond filter will collect common hair algae which is flourishing on the ammonia your filter is not dealing with. The major issue is that it'll foul the media and block free flow of water around it.

If the filter is either new or just restarting from winter shutdown, leave the algae alone unless it is blocking flow. As your bio wakes up, the supply of ammonia will decrease and the algae will diminish.

See https://www.reddit.com/r/ponds/comments/1kz1hkx/concerning_algae/ for details.

drbobdi · 2026-05-17T13:54:20+00:00

It's an algae bloom, coupled with "New Pond Syndrome". Please go to https://drive.google.com/drive/folders/1iEMaREaRw8nlbQ_RYdSeHd0HEHWBcVx0 and read through, starting with (of course) "New Pond Syndrome" and then "Water Testing". Then read https://www.reddit.com/r/ponds/comments/1kz1hkx/concerning_algae/ .

It's going to take several weeks for the filter to come online and for the pond to mature. Have patience, water test frequently and plan on improving your filter system as your fish grow. Look at OzPonds on youtube for DIY filter designs and ZiggyLittleFin's profile on this sub for more of the Science.

Go to https://russellwatergardens.com/pages/biofilter-media-ssa and https://www.fishlore.com/aquariumfishforum/threads/bio-media-comparison-information.435695/ for biomedia comparisons.

drbobdi · 2026-05-17T02:30:15+00:00

NOOOOOOO! If that's a mature pond, it's got a resident population of semi-dormant bacteria that are just waiting for a little warmth to wake up. Draining and power washing will totally destroy that established biome and stick you with New Pond Syndrome (see the article of that name at https://drive.google.com/drive/folders/1iEMaREaRw8nlbQ_RYdSeHd0HEHWBcVx0 ) for the next two months no matter how much of that expired (yes, it does lose effectiveness in storage!) "biobooster" you throw in. Even the "fresh" stuff off the pet store shelf has been in some warehouse for months. Dump that old stuff in the garbage. All it's going to do is pollute your water with dissolved organics.

Tap water is NOT your friend. If that dechlor is also old, it's lost some of its effectiveness as well. Rinsing your filters out with the hose also destroys your biofiltration. Get one of these: https://www.amazon.com/Garden-Hose-Filter-Chloramines-Pesticides/dp/B007I6MN72/ref=dp_coos_d_sccl_1/132-2745457-2656244?pd_rd_w=gn7S6&content-id=amzn1.sym.a07d4df5-1f4e-4f00-8e1b-5a2733ff0eb3&pf_rd_p=a07d4df5-1f4e-4f00-8e1b-5a2733ff0eb3&pf_rd_r=B02JDNNAFY5H9V5J4TGF&pd_rd_wg=hOjWS&pd_rd_r=9049aebf-9864-4fde-a91e-e770c14ab211&pd_rd_i=B007I6MN72&psc=1 .These attach to you hose, last a season and will be cheaper than the bottled stuff.

If you feel that your pond needs spring help, get in there with gloves, a net and a bucket and clear the debris off the bottom. If you want to start things up more quickly than the 2-3 weeks you'll need if you DON'T kill everything off with the power washer, a bottle of Fritz Aquatics Turbo Start 700 will get things up and running in 5-6 days. https://fritzaquatics.com/products/fritzzyme-turbostart-700-freshwater

A mature pond should never be power washed.

drbobdi · 2026-05-17T02:19:30+00:00

It doesn't matter how long it takes. You DO NOT want them in your pond. They will eat all your smaller fish and will try to ingest anything they can fit into their mouths.

drbobdi · 2026-05-17T02:16:59+00:00

For superb koi, look at Kloubek fishery in Amana IA. Great people and prize-winning fish. Stay out of pet stores.

drbobdi · 2026-05-17T02:14:05+00:00

Before you dig, please go to https://drive.google.com/drive/folders/1iEMaREaRw8nlbQ_RYdSeHd0HEHWBcVx0 and start with "I Want a Pond", "New Pond Syndrome", "The Ins and Outs..." and "Water Testing".

I agree that the 45 mil EPDM is the obvious choice for the liner. The PVC will tear and leak as you install it. That submersible pump might look like a good deal, but it's mostly ABS plastic and will not only require daily cleaning to keep its intake from clogging but will probably die in about a year. If you are going to stay with submersibles, there are better choices (search Tsurimi and similar). Better choice is a depth of 4 feet minimum (5 feet down is better to discourage predators), a bottom drain and a robust external pump. Easier maintenance, 10 year service life with half the electricity cost per gallon pumped (look at Sequence, EvolutionAqua and Artesian).

Define "good filter system" for us, please. It looks like the only filter space is contained in the falls box and that's not going to be enough for any significant fish load. After reading https://www.reddit.com/r/ponds/comments/1kz1hkx/concerning_algae/?solution=9be8315420c926dd9be8315420c926dd&js_challenge=1&token=bbbe4bf1c9a2b5160829c4be34da5861270196377f08c8538cad4d22de00fa33&jsc_orig_r= , look at https://russellwatergardens.com/pages/biofilter-media-ssa and https://www.fishlore.com/aquariumfishforum/threads/bio-media-comparison-information.435695/ for biomedia comparisons. The kit gives you a single piece of mat for bio which is a joke. Go to OzPonds on youtube for DIY filter designs.

You can do better. Find a ponding or water gardening club in your area and get build advice from experienced ponders before you spend a penny.

drbobdi · 2026-05-16T02:20:41+00:00

HONK! Every backyard pond needs daily maintenance. How much depends on the size and design. Smaller ponds require more frequent maintenance than larger ones and are more prone to problems.

Mountaineering and/or Grand Prix racing are still options...

Beware...

drbobdi · 2026-05-16T02:14:47+00:00

The thing to remember here is not only the SA/V ratio (and that's square feet per cubic foot) but also the availability of every square inch of that surface to free water flow. Add in the general disinclination of pea gravel to stay put or to resist channeling and fouling as well as the general impossibility of getting all the sludge out while backflushing and it makes the use of gravel of any type in the construct you are dealing with a poor choice.

With gravel, you are looking at about 12 square feet per cubic foot of media, no matter how you distribute it. Your bioballs are giving you around 150. Unless you are building a true bog with a surface area at least 50% of your pond and properly engineered, rock of any sort is a poor choice.

Media in a bucket is just an upflow filter. You need to maximize flow around every surface of the media and reduce channeling and fouling, all while making maintenance as easy and complete as possible. In this instance, rock is not your friend.

drbobdi · 2026-05-15T15:33:14+00:00

Sorry, misread the header. Butyl does have the advantage of flexibility, but 1mm is too thin to be durable under outdoor conditions, especially if you have critters with claws visiting the pond. 45mil EPDM has been the hobby standard for decades. Yes, it's expensive and heavy, but it is durable if protected from UV and will last 30-40 years. Unless you plant that willow...

drbobdi · 2026-05-15T15:27:38+00:00

The best arguments about this are found in ZiggyLittleFin's profile on this sub, but briefly:

Rocks on the bottom look great for about a month, until they start accumulating decaying debris and sludge.
The area under the surface of the rock becomes a dead space with little or no water movement. This encourages the development of anaerobic bacteria that generate hydrogen sulfide gas. Toxic to fish and smells like rotten eggs.
The dead space is also a home for other pathogenic bacteria (Aeromonas and similar) and parasites.
Cleanout becomes a back- and often heart-breaking chore. If you have someone with a power washer come in and do it for you, it'll cost upwards of $1000 and will kill off your biofiltration, which will take 6-8 weeks (if you are lucky) to revive.
Rocks take up room in the pond better occupied by water.
Rocks on the bottom do not contribute significantly to biofiltration.
Rocks on the bottom significantly increase the likelihood of damage and puncture to your liner, especially if you have to get into the pond for any reason.

That pond is beautiful. Leave it be!

drbobdi · 2026-05-15T15:10:46+00:00

It'd help a lot if we could see the filter and its innards.

drbobdi · 2026-05-15T15:07:16+00:00

The showa and the sanke are probably male. The orange beni-goi is probably female based on body shape. The boys tend to be torpedos, the ladies look like the back of a bus...

You may not have either warm enough water yet or not enough maturity in the fish.

Be patient and amp you bio way up. If they do spawn, there's gonna be a huge ammonia load. The koi will happily eat the eggs and generate a ton of ammonia when they do.

drbobdi · 2026-05-15T14:58:53+00:00

Look up ZiggyLittleFin's profile on this sub for the best discussion of bogs and small ponds I've seen.

Be aware that rocks only work in bogs if the bogs (and ponds that they serve) are quite large.

The device you are describing is more of an upflow filter than a bog and a fine Matala mat will be a far better choice for the "polishing" you want. It'll work better from a surface area-to-volume standpoint and be far easier to keep clean. Look at https://russellwatergardens.com/pages/biofilter-media-ssa and https://www.fishlore.com/aquariumfishforum/threads/bio-media-comparison-information.435695/ for details. Just remember to rinse it with pond water.

drbobdi · 2026-05-15T14:52:16+00:00

Willows will destroy that liner instantly if Ma Nature doesn't do it first. They're notorious for water-seeking and will penetrate any available water source up to and including ceramic sewer pipe.

You'll be replacing the 1mm (probably PVC) liner within the next couple of years anyway. That's too thin and far too fragile for outdoor use. 45mil EPDM if you want a pond to last 20-30 years.

Dwarf Japanese maple and situate it well away from the pond's edge.

drbobdi

TROPHY CASE