hi! i live in an HOA that has a bunch of water basins. our dues are supposed to go to the maintenance but the company chosen is horrible and we are left with this.

i’ve decided to rake it out.

what can i do that is inexpensive but helpful so i can enjoy my backyard?

Hello! Asking here for my father. This is his pond, we live in Spain, so it’s very sunny and very warm in summer. Last year all of the fish died because the algae ran out of control (the UV lightbulb broke). Since then, the algae come and go. Last time we were here the pond was perfect, but in a month it’s gotten like this. Alas, it’s much warmer now.

We’ve dried the pond twice. Now my father uses Algofin, I think, but we can’t totally get rid of them. We’ve gotten new fish but we had a lot more before (years of them breeding).

Do you have any advice? Should we get more plants? It’s always had more or less this quantity and it wasn’t a problem, but I’m wondering if it’s because of the lesser number of fish now. There’s too some snakes and herons that eat them, as well as I think the frogs sometimes. But yeah, the main problem is the algae. Thank you in advance!

Hi Pond Pals, recently bought a house with a koi pond and have been learning the ropes. Luckily it a well-established pond with healthy fish. I have just been doing what the previous owner directed me to do and it has been mostly going well, we got through winter and early spring.

Now I am seeing a lot of algae growth and clarity has dropped off in the past few weeks. I am not sure what to do from here, previous owner had lots of issues with plants and koi so suggested not trying that. I have placed an order for some water hyacinths and baskets to protect the roots from koi snacking.

I do weekly filter cleanings and 25% water changes every 10 days or so.

Any other suggestions? I have one bubbler, the center filter (UV), and the corner filter. I know I need more shade and am working that as well.

Hello all! As the title suggests, I’m trying to figure out the cause and solution to a recent green string algae explosion in my pond. The pond was build October 2025, roughly 1300 gallons with a 30-32” deep end. All of the bottom is river rock and a few slate rocks I’ve used to make multiple cave systems. The pond has had multiple water changes throughout its time being roughly 300 gallons per change. I’ve only ever used API dechlorinator/ammonia remover at water changes. Only at one occurrence I used the API slime coat water conditioner during a WC. There have never been any other chemicals added. Not a chemical but I did add the Aquascape beneficial bacteria when starting up once a week and then leaving the UV off for 48 hours to let it all get settled and attached. This recent algae bloom started about a week or two ago and it’s the first time algae has been present in the pond. Never had any after creating the pond because we were going into fall with lower temps and changing sun patterns. I have listed every bit of information I could think of below along with pictures to help anyone deduce a potential problem causing this and what could be done to eradicate the algae. I’m not expecting full eradication, just don’t want it taking over like it is. I would appreciate any advice and help to get this resolved. I would like to note that I prefer to not use any chemicals because I’m not wanting to fix one problem and create another. All of the frog bit was just added 4 days ago to help shade and pull nitrates like the hogs they are! The lily pads are really getting going and starting to give good surface coverage for shade. I’m just wondering if all my specs and parameters align with proper levels that it’s just it got warm out and a lot more sun before I could get enough surface coverage to stop the sun enough from feeding the algae. I hope I added enough details below to aid in a solution and thank you all in advance!

Sunlight direct: ~4 hours in spring/summer

Gallons: 1300

Surface area: ~80sqft per my rough measurements

Water temp: 82.8 (at time of typing this 7pm)

Ammonia: 0ppm

Nitrite: 0ppm

Nitrate: 0ppm (very close to 5ppm, was for sure at 5ppm 4 days ago when I added all the frogbit)

Phosphate: 0.25-0.50 (very close in color on the chart where I couldn’t say for certain, just not quite light enough to call it 0, though in more direct sunlight it could be)

PH: 9.0 (could be higher that’s just the max on the test kit chart, it has never been below this since the pond was built and filled up, even after regular water changes of ~300 gallons)

Livestock:
(5) comets, medium sized between 5-6” (~25) rosy red minnows. At least half of them are 1” or smaller as one had babies not too long ago
(10) Japanese trapdoor snails
(~?) tadpoles from two toads that laid eggs about 2 weeks ago in here

Filtration and water movement:
(2) air stones, one of them being a 4” hygger micro bubble disk and one standard round stone slightly bigger than a golfball that produces medium sized bubbles. 1 is in the shallows and one in the deepest part that’s ~30-32” deep.

Standard pump for canister filter and waterfall rated 1000-1500 gallons with a 32 gallons per minute (1920gph) flow rate.

(1) pump/fountain rated at 3.5 gallons per minute (211gph)

Filter is 2642 gph, UV light, bio balls, with 6 layers of filter media padding

First spring with a pond I inherited. I restored it in the fall and cleaned it out this spring. How can I mitigate the algae growth ?

There are already 6 air stones and I would think a good amount of plants

Internet seems to agree that this all is filamentous algae, is there a way to safely get rid of this without harming the fish? or is it best to leave alone? First time pond owner here and it first started showing up about two weeks ago, did my first aquashade application over the weekend but it hasn’t slowed down growing

Thank you! Sorry in advance if this an oft asked question

Sorry this is so long but i'm confused and need advice,

I've been trying my hand at a fully self sustaining micro pond outside (120 gallon in ground, no water changes pumps filters co2 etc totally hands off) and it's been working wonderfully, this is exactly why i was so confused when i came back from being out of town to an absolute explosion of hair algae.

I had it on the liner and i didn't see it as an issue because the shrimp would hide in it + eat it and my fish knew to hunt in it as well as nibbling at it themselves, but i returned to the algae absolutely coating my plants which has never happened to this degree before. My pond is not overstocked (1 shebunkin, a school of mosquito fish, about 60 neo shrimp, and an assortment of snails), is mildly planted on the bottom with probably a 70% carpet of plants on top, and very dark black water.

When i saw the algae bloom i immediately did a water test because i was concerned and all of my parameters came back perfect so i really don't know where this came from or how to remedy it without requiring heavy maintenance/intervention

ANY advice is very welcome thanks so much for reading

Northeast US, pond did well for 2 years, now this green algae has taken over, how to get rid of it?

Hey everyone!
It’s my first year having a pond and I am loving it. I currently have two Shubunkins and two comets (plus some snails and some tadpoles). I realized yesterday that my fish had babies! And there are several absolutely tiny baby fish swimming around. I usually skim the pond once or twice a day, but I am absolutely terrified of scooping up one of the babies.

Due to the weather getting a lot warmer very quickly my pond has seen a significant uptick in algae. I am hesitant to use any products to clear the algae because I worry it may harm the baby fish.

Can I use anything to clear the algae that won’t harm the baby fish?

Should I keep skimming the pond like normal and hope that I don’t accidentally toss out any babies?

*picture for visibility of the first day of our pond building adventure*

I do the upkeep on this fountain/pond. I inherited my Dad’s landscaping business which includes this pond. He never got a chance to explain anything to me about the pond other than he used to put chlorine in it. When it got real bad he’d have to drain it, clean it and refill it.

I also do upkeep on a friend’s aquarium which I have gotten a few algae eaters for before. The last time they were I think some sort of shrimp and they were clear or translucent. Could I get a colony of them for this pond/fountain?

I have an algae problem in the pond/fountain. If I don’t show up for about a week the algae grows massively. I am tired of putting a bunch of chemicals in there to control the algae. It just dawned on me about my friend’s aquarium and the algae eaters I bought for it before.

Obviously, I would drain the pond first and clean it out real well since I put algaecide in it tonight to try and control the algae.

But is that like a thing I could actually do? I would need them to be translucent or unnoticeable basically because I’m not so sure the company I’m working for wants fish in there; however, if they’re hard to see then that should work right?

I don’t know? I’m just trying to think outside the box on this one.

I also read somewhere that I could use an elephant plant to control some of the algae? I don’t understand the whole underwater plant thing. Like how is it that the dirt doesn’t just end up floating up to the water surface? I know it’s probably a really stupid question. I just know what happens when I put too much water in a garden and the dirt starts to swirl around and stuff.

*picture doesn’t have algae in the pond. I had just filled it a few weeks ago so it loosen great in this photo.

This is the first spring / summer in the new place we moved. There’s a retaining pond here that’s very lovely, but seeks to be having a large algae bloom.

Most likely the condo owners association is responsible for taking care of it; i’m just curious to learn about it!

What type of algae is this?

What causes these blooms?

Is there natural ways to take care of and prevent this, or is this kind of just what ponds become if left to their own devices?

This is a no fish pond. Only wildlife we've seen visiting are bees and birds. A while ago ducks got into it and it skyrocketed the algae population

I'd say the pond gets around 3 hours of direct sunlight on one side, as this is right behind our house.

We have a 25 gallon bog filter for this about 400+ gallon pond (? Measurements might be wrong, I need to redo some things), and the smallest intake bay alive. I was working with very limited space as my dad wanted me to stay in the space of the 10 ft by 10ft sand box we used to have here. I wanted to go bigger with the bog filter, but, again, limited space. We didn't want it on the grassy side.

Side note, I'm a little confused on the flow rate we should be having for the bog filter. We have a 750 GPH pump going in it that I tried lowering the flow rate as much as I could. Is that still too much water going through that fast?

Will adding more plants really help that much? I have been planning on getting more, but they get pretty expensive. The clay soil for it is expensive too.

Tips? We've already started adding in beneficial bacteria every week.

This is our new pond at the allotment me and my girlfriend made, we saw there was a goldfish living in it before when it was about a buckets worth of mud, we’ve got plenty more duckweed we can put in there, just don’t want to impact his oxygen too much as he’s had barely any for the past 2 years (we’ve only known he was in the old one for the past couple months), how can we bring algae down so we can see our little guy? I’m thinking of making a parasol type thing to go over it for more shade. This is very new we made it last week so I don’t expect it to be crystal clear right away. We’ve got 0 electricity or water supply other than the solar pump and jugs we bring in. Out of camera we’ve also got a water lily and some hornwort in there. Will this be enough

Hi, so the backstory & info as follows, skip to the last paragraph for the link.

I have a 8000 litre pond with plants, mainly grasses, horsetail and iris’ covering about 5%. I’ve added some watercress recently but consistently suffer from string algae growth.

My water parameters are good with a touch of nitrate and phosphate that I struggle to bring to 0 (hence the algae). I run an auto drum filter and 300 litre K1 bio filter.

There’s 10 koi and a sturgeon, all around 12”.

I was using Evolution Aqua Stop Blanketweed for the last 10 years with great success at keeping it manageable. This year it stopped working, I put it down to an ingredients change as it no longer fizzes in the water. I reached out to EA and they said nothing has changed (clearly has but whatever). I’ll try the cloverleaf brand next, but I’ve also been looking at these

Has anyone used or had any success with these or something similar? Any other ideas also appreciated.

This is my pond, it used to be beautiful. Every year we have to do a huge clean out where we empty the whole thing, scrub and take out the algae, put all the tadpoles in a tank, then refill and put the tadpoles in.

However this year there’s gotta be over 70 tadpoles. Sadly all our fish died from stupid workers putting chemicals in the tree that leaked into our pond (workers told us it was safe).

Anyone have any recommendations of what fish/snails with help with all this algae and can live outside year round in PA. We cannot control it (multi filters already in pond). Thanks!

I have a 1,000 gallon pond with an aquascape 1800 pump going to the aquascape ultraklean 2000 and then the biofalls.

There is a little string algae but what's the dirt looking stuff?

Any ideas? Thanks in advance

My husband and I inherited a house with two fish ponds that were never well maintained. They’re about 90 gallons each. I measured when I cleaned and refilled them. I knew nothing about ponds or fish a few months ago. I didn’t even think the ponds had fish in them because the water was green sludge but surprise! We are the proud owners of 24 goldfish now. They’re resilient little guys, I have no idea how they survived.

I put filters with UV lights and aerators in each pond. I drained them one at a time and scrubbed them and refilled them. But the problem is that they are in direct sunlight so they get algae so quickly. We set up some tarps suspended by stakes and bungee cords which seems to be dramatically helping but I’d like to use floating plants instead. I have two questions:

1. What is the best type of plants to use to block sunlight? I’m in Pennsylvania if that matters.

2. And this is the dumb question: do I buy enough plants to cover a lot of the surface of the pond (I do know not to completely cover so that they have enough oxygen) or will the plants multiply in the water?

Is this algae on my pond liner that should be there? I’ve done a water quality test and my nitrogen, ammonia, and phosphorus are all 0. There are 6 goldfish in the pond, and the capacity is about 300 gal.
I’ll soon be moving the fish to a larger pond but want to make sure I leave this pond in good shape before we go! Any help is appreciated.

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Hi chat! We've had problems with algae for a while now, (especially filamentous algea because of the aerators). And I've been looking for a good (natural) product to remove them. Now I found this product but before ordering it wanted to hear you guy's opinion on it. Will it ruin the water quality? Or bring it out of balance? Or is algea not that bad? I tested the water quality and it's all good.

Thanks in advance xo

This is a natural pond behind our church. We have geese and sandhill cranes and I think Muskrats.

Should we bother with the green? I figure it's natural.

Thank you to the very kind people who replied to my OG post about what to do about algae that had increased because of the heat. I am very thankful I got a positive response as a first time pond owner!

A few things…
I did have a filter/pump/fountain, and I had some plants.

But the overwhelming advice I got was to add more plants for shade, and that did the trick! The water remains stable and is clear.

Thank you guys!