Took over existing pond, fighting algae for weeks now

[Rurik]

We purchased a home that has a 500 gallon pond in the back yard, with a PF-1400 pump/filter (designed for 1400 gal) and a single waterfall element (with its own pump). There are two 10" koi and about 15-20 goldfish (too many, in my opinion, but that's another matter...). The pond sits in direct sunlight for about 4-5 hours per day.

After winter passed and we set to doing maintenance, we noticed very green water in the pond. No string algae, just green cloudy water. The fish are only visible 1-2" below the surface.

The waterfall had 1/4" of green algae gunk, with the consistency of pudding, all over its water-bearing surface. The pump filter was caked with green, and its internal UV lamp was not functioning.

We replaced the filter elements and the 11w UV lamp on the pump, and scraped most of the algae gunk off the waterfall. We added two barley straw floaters and greatly reduced feeding (to about once every few days).

No change in the water... so, I purchased a second 9w UV lamp and plumped it in-line with the waterfall pump. I've tried various flow rates through the filter, but no effect. The lamps have been running 24/7 (as have the pumps and waterfall).

After over two weeks of trying to reduce the algae, with the UV lamps running, we reluctantly resulted to chemicals this week with TetraPond Algae Control. After three days since applying it, no change.

We've now been fighting the algae for almost a month and I'm getting very worried. We have a house opening party this weekend, and I've given up having the pond look clean for it. I'm worried if there is a larger issue at play.

We do have little kids, and I was worried that they were feeding the fish when way too much, so I've locked up the food and do the feeding myself. We took a water-strip test, which shows that the pH was just a bit too high.

As new pond owners, is there something that I'm missing in our treatment of the water?

Pictures:

 

[HTH]

Two weeks is not an overly long time to work on clearing an algae problem.

First think of the algae as a symptom instead of the problem. Then when you have ruled out things that might cause the algae go after the algae directly.

Any idea how fast the food was going away. As you said it could be the kids have been feeding way too much too often and the algae is keeping the water livable for the fish.

Normally a water change only makes a algae bloom worse but if your water is crazy high in nutrients from overfeeding it may help. Still may get worse before it gets better,

What was the pH ?

 

[Rurik]

That two weeks isn't overly long is good news. Most of the stories I've read on here have been that issues were cleaned up within 3-5 days.

I will at least monitor it for another week or two and attempt to do a 10% partial water change.

My wife had to correct me on the pH level. It was actually a tad low, 6.8 from her recollection.

We did track the food consumption over time and kept the food at an amount where they ate it within 2-3 minutes. They were very slow eaters though; one poking up to snag a bite every 5-10 seconds.

 

[gblazzo]

I know this is coming much later since your last post, but its still good info. Keep in mind that algae feeds on nutrients in the water and if you dont have any aquatic plants in the pond as the photo suggests, your water will stay green all summer. lily pads, hyacinth , cattails and many other plants feed on nutrients in your pond and also release oxygen into the water. they compete with algae for the food source and also provide shade which is good because algae also needs sunlight to grow. In my opinion, more aquatic plants means more oxygen for your fish and less algae. This way no chemicals are being used and theres no risk of harming the fish. Be patient , keep researching and enjoy it.

 

[HTH]

Need to note that only plants with roots in the water absorb nutrients. Potted plants don't.

 

[Rurik]

Thanks for the feedback. We've been monitoring it, and it has progressively gotten worse. After scrubbing our waterfall clean, within a week there was a 1/4" thick slime of algae covering it. It's definitely growing faster (See picture at end).

We called around to a few local companies. Best we've found was $750 to do a water replacement and consultation. Before we go to that step, we're going to try the plant approach. We do have very few plants, and more would likely make a difference.

FYI, here's the waterfall a week after cleaning it. The "clean" area in the middle is where I scraped it toward the left.

 

[fishin4cars]

Got some questions and suggestions, First off, what are the dimensions of your pond,(Length, width, and depth) It looks quite a bit larger than 500 gallons. My bet is your filter is quite the opposite rating than your thinking. Second, What are all your water test readings, Ammonia, Nitrite, Nitrate, PH, KH levels? Third, How often do you clean the filter and when you do, do you use tap water to clean or pond water? Forth, how many hours of full sun expose is on this pond?
Suggestions that can be done with minimal cost, addition of plants,, as stated the more roots that are growing in the water column the more nutrients absorbed, also the more surface area covered the less sunlight that can penetrate into the water. BTW, Leaves shade the pond as well and help maintain more stable water temps, the warmer the water the more algae like it! Water lettuce and water Hyacinth's do both and do multiple. Marginal's use the nutrients and only add limited shade, water lilies can add a lot of shade but only use minimal nutrients from the water. Shade the pond, Until you can get more plants the next best thing to help is shade the pond. Shade cloth, a small tarp, anything that can help keep the sunlight off the pond until you can get more plants growth. When doing water changes, TRY to take as much from the mucky area as possible during the water change, try not to disturb the bottom as much as possible but simply remove what waste you can a little at a time. Add oxygen any way you can, the higher the oxygen the better the Bio can help assist breaking down waste that is feeding the algae. String algae can be your friend, Leave it on the water fall until the water is clear, it removes a great amount of nutrients and is actually very healthy for the fish to eat, plus it's easier to get under control once water balanced is achieved. One last thing, Is there anything at the top of the water fall that is being used as filter material, If not make use of that area! It is very easy to make something that will help in filtration and can be added with little to no cost. With a little $$ you can even add filtration that is quite effective depending on what is there and how the water is being returned to the pond, Examples, filter matting such as Matala, Bio balls in a bag, lava rock in a bag, cut up pieces of old tubing or plastic pipe, the list is endless. There is a lot of hope for this pond, but some improvements need to be made or the problem isn't going to fix itself.

 

[adavisus]

Feeding the fish is fertilising the algae....

When 60% of the pond area is dominated by desirable well chosen aquatic plants, you will find that will suppress algae

Especially if you don't fertilise the algae...

Regards, andy
http://www.flickr.com/photos/21940871@N06/
http://swglist.wordpress.com/

 

[Dave 54]

I know this is coming much later since your last post, but its still good info. Keep in mind that algae feeds on nutrients in the water and if you dont have any aquatic plants in the pond as the photo suggests, your water will stay green all summer. lily pads, hyacinth , cattails and many other plants feed on nutrients in your pond and also release oxygen into the water. they compete with algae for the food source and also provide shade which is good because algae also needs sunlight to grow. In my opinion, more aquatic plants means more oxygen for your fish and less algae. This way no chemicals are being used and theres no risk of harming the fish. Be patient , keep researching and enjoy it.

If thats so why as a koi keeper with no plants in the pond have I never had much of a problem with green water ?

rgrds

Dave

 

[Dave 54]

The problem with inherited ponds is you dont know their history
Ok can you tell us when the bottom of the pond was vacuumed of dead leaves and gunge ?
When was the filter last cleaned ?
I note dead leaves in the photo of the waterfall, where there are trees there are dead leaves.
I also not that you have no Oxygen running to your pond via airpump .
Can you correct these please,

rgrds


Dave

 

[HARO]

Need to note that only plants with roots in the water absorb nutrients. Potted plants don't.

Where do you GET this info? :dunno:
John

 

[koiguy1969]

my plants are potted.. but potted in river rock. so they have direct access to the pond's water....

 

[Rurik]

Thanks for the responses. I am currently on the road this week but will be taking measurements and chemical samples again. I'll post those early next week.

 

[Rurik]

Got some questions and suggestions, First off, what are the dimensions of your pond,(Length, width, and depth) It looks quite a bit larger than 500 gallons. My bet is your filter is quite the opposite rating than your thinking. Second, What are all your water test readings, Ammonia, Nitrite, Nitrate, PH, KH levels? Third, How often do you clean the filter and when you do, do you use tap water to clean or pond water? Forth, how many hours of full sun expose is on this pond?

The old owner noted that it was 500gal. It's basically 7' x 11' and a max depth of 20". As a box, that suggests about 700gal, but with curved walls it may be close to 500.

The filter comment was based off the model, Laguna Pressure-Flo 1400 (PF1400), which is advertised for ponds up to 1400gal.

A water testing today read:
pH: 7.0
Alkalinity: 120ppm
Hardness: 150ppm
Nitrite: 0ppm
Nitrate: 20ppm

We replaced the filter in April when we started fighting this issue, but do not know how long it had been since last changed (good estimate is 6-9 months). My goal was to rinse it off next week at the two-month mark. That would be done with hose water (well water). I'm not even sure how one would use pond water to rinse. Fill a bucket and continually dunk the filters in it?

It has some shading, but does get about 4-5 hours of direct sunlight.

Suggestions that can be done with minimal cost, addition of plants,, as stated the more roots that are growing in the water column the more nutrients absorbed, also the more surface area covered the less sunlight that can penetrate into the water. BTW, Leaves shade the pond as well and help maintain more stable water temps, the warmer the water the more algae like it! Water lettuce and water Hyacinth's do both and do multiple. Marginal's use the nutrients and only add limited shade, water lilies can add a lot of shade but only use minimal nutrients from the water. Shade the pond, Until you can get more plants the next best thing to help is shade the pond. Shade cloth, a small tarp, anything that can help keep the sunlight off the pond until you can get more plants growth. When doing water changes, TRY to take as much from the mucky area as possible during the water change, try not to disturb the bottom as much as possible but simply remove what waste you can a little at a time. Add oxygen any way you can, the higher the oxygen the better the Bio can help assist breaking down waste that is feeding the algae. String algae can be your friend, Leave it on the water fall until the water is clear, it removes a great amount of nutrients and is actually very healthy for the fish to eat, plus it's easier to get under control once water balanced is achieved. One last thing, Is there anything at the top of the water fall that is being used as filter material, If not make use of that area! It is very easy to make something that will help in filtration and can be added with little to no cost. With a little $$ you can even add filtration that is quite effective depending on what is there and how the water is being returned to the pond, Examples, filter matting such as Matala, Bio balls in a bag, lava rock in a bag, cut up pieces of old tubing or plastic pipe, the list is endless. There is a lot of hope for this pond, but some improvements need to be made or the problem isn't going to fix itself.

Good advice. My thoughts are to put the winter netting over the pond and cover 3/4 of it with a tarp for the current time.

I cleaned the water fall out and it did have a filter pad. However, probably a bad call, it was so clogged with gunk that it was tossed. I will need to source another, and will likely go with the bio ball in a bag approach as well.

We have added a few additional plants in floating baskets, but no major differences noted in the past few weeks.

The problem with inherited ponds is you dont know their history
Ok can you tell us when the bottom of the pond was vacuumed of dead leaves and gunge ?
I also not that you have no Oxygen running to your pond via airpump .

I don't know when the pond was last vacuumed, unfortunately. And, you're right, there's no air pump. There is a pump in the garage. I think it's time for me to take it out and determine how to install it.

 

[Rurik]

There's been a noticeable improvement over the last week. Before we couldn't see the fish at all, except the tips of their mouths when they came up to feed. Now we can make our their shapes about a foot below water.

I have an aerator installed with a large bubble disc (it's just thrown in now, will clean up install after the pond is clean). I've also been exchanging water weekly, and am just now seeing the signs of it getting a tad clearer. We've just put a tarp over 3/4 of the pond to block most sunlight, letting sun in just where the plants are. I'm hoping to see additional improvement over the next few weeks as well.

Fingers are crossed.