Newbie to outdoor ponds needs help with big pond

[khelvan]

Greetings!

We have an outdoor pond that we use for irrigation on our property near Sacramento, California, and when full it is about 175,000 gallons.  When putting in the pond we lined it with a heavy plastic to prevent problems with the soil clogging the irrigation system and to help keep the water clear.  We have a small water fountain and several aerators.  Currently the only thing on top of the plastic are some of the rocks that we used to line the top of the pond, and some sediment that comes in with rainwater or from the pipe that brings in water from the county's irrigation ditch.

The county seeded our pond with "mosquito fish," which I have no idea what their true name is.  We have been having a real problem with algae, as the water we use to irrigate our lawn is channeled back into the pond through the landscaping, bringing all sorts of nutrients into the pond.  We have tried using a product called "aqua-tron" that supposedly controls algae through adding beneficial microbes to the water, and this helped, but the water is still quite murky.

We're not quite sure how to proceed.  Our primary objective with the pond was irrigation for the land and aesthetics for the landscaping, but having the water so murky was not expected.  We were considering adding another species of fish to help control the algae, but we're not sure which would help.  We were thinking of aquatic plants, but were not sure what sort of underwater plants we could add without fear of either breaking our lining or clogging our irrigation pumps.  We were also considering water lillies or hyacinth, but have fears of it becoming invasive and taking over the pond, or again clogging the irrigation system.

Does anyone have suggestions on how we can improve the situation?

Thank you!

[Esther]

I don't see fish ever clearing your algae problem. I see them adding to it. They poop and that adds to the nutrients in the water that feeds the algae. Plants will break down and add gunk to the water but on the other hand, they'll eat up some of the nutrients and shade the pond. I'm not knowledgeable enough about a setup like yours to really help. The first thought I had was chemicals but when your water is irrigating edible food, I can't see putting more chemicals on it. Probably somebody else will know.

Have you Googled "irrigation pond"? Or called someone who installs them or sells equipment for them?

[Johns]

Call and talk to the people at Aquatic Eco Systems.  They will help you solve your problem.  http://www.aquaticeco.com/   1-877-347-4788 

[Sunbeam56]

How deep is the pond?

If all you want is clear water to irrigate - you can't beat water hyacinth. Yes, they are invasive. But they are EXCELLENT filters. They are even used in some municipal wastewater treatment plants because they not only take up the nutrients, but also heavy metals.
Because they grow like crazy when they are happy - you may have to create a big compost pile where you can harvest the hyacinths occassionally to reduce the crowding.

But they are illegal in some states, Texas being one.

Suggestion number two would be any kind of a floater. If you shade and filter the water, you will have clearer water.
Plants in the water also provide some filtration - but not necessarily the same kind of clear water you may need for your ag use. Water lettuce, duck weed, azolla.

Then you get the semi-floaters. Plants with roots down, but floating leaves - water lilies being an excellent example. Lotus hold their leaves above the water - so are less effective at water clarification - but a pond full of lotus is a spectacular view, as Joyce's pond shows well.

Are you interested in attracting wild life or birds?

[khelvan]

Thank you for the help!

At its deepest the pond is about 10 feet deep.  There is no need to attract wildlife or birds - we have wild turkeys roaming the land already tearing up our plants, and occasionally other birds find there way here.  Some ducks made the pond their home for a while, though the lack of underwater vegetation meant they didn't stay very long.  Really, the pond is for irrigation and to be a tranquil place for we humans, and anything else is secondary and a pleasant bonus, as long as the focus of our maintenance is on those two objectives.

With the scarcity of soil, will a plant like water hyacinth be able to live?  Or does it use the water alone for nutrients when soil doesn't exist?  Will the hyacinths grow and clog the pumps?  We are in California, and I am not sure of the legality here.

I am afraid that with any plant, though especially floaters like duckweed, the attempt at finding a solution would bring even more problems.  Is there a way to introduce a filtering plant while ensuring it doesn't create more issues with the pump/overtaking the whole pond?

Thanks again!

[Esther]

Call the experts.

[KatFish]

WH just float on the top of the water and dangle their roots down to suck up nutrients.  As time goes on, they will spread, so just pull some out once a month or so when it gets to that point.  They wouldn't cause any problems with your pumps that I can see.  Plus, you can get some pretty flowers 

[LeeAnne151]

Frost will kill water hyacinths.

Have you tried contacting your local university extension office? They could route you to the right person if they don't know how to fix your problem.

[Mikey]

Without a biofilter or lots of shade I'm guessing your water will always be murky.  That's just how natural ponds tend to be.  I realize you have lined your pond, however, Koiphen has a "mud pond" forum that may be of assistance: http://www.koiphen.com/forums/forumdisplay.php?f=108

[cokeisit]

When you say murky, what do you mean?  If your pond is murky due to suspended particles, then you may need to look into a flocculant to help settle it out.  If it is mud and sediment suspended in the water column no bacteria or anything else will really help that.

Tilapia is a fish available in Texas that does feed on string algae, if that is the type of algae you have.  However, they are a warm water fish and may not make it through the winter, depending upon where you are.

Generally, to control algae in a pond like yours you can aerate, which it sounds like you have plenty of, add beneficial bacteria which you say you have done and then also add a lake dye to help filter out the sunlight which the algae uses to grow.  Those three things together can have a lasting impact.

BTW...on your aeration systems, are you using bottom based diffusers?  A pond of your depth should probably be using diffused aeration.

[PondmaninAL]

Depending on what zone Sacramento is in, tilapia may do well. Where I'm at in Florida, the zone is 9b and tilapia do well here but as Esther has mentioned, that will only add to the problem. Depending on how the intake of your irrigation system is designed, water hyacinths would be perfect. Also, tilapia cannot be introduced into a pond with plants, their main food is plants, especially if they run out of algae and if they run out of plants, goodbye mosquito fish. So, keep the mosquito fish and get some water hyacinths. Just keep the WH's from the intake with a screen.

Happy ponding,
Scott

[miguynmkoi]

Water hyacinths are sold in nurseries in Southern California and they're great in warm weather but messy in the colder temps.  They do not need soil to survive as they "float" on the water as Sunbeam described.