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100 x 50 large pond maintenance for swimming

Posted by dspero80 Michigan (My Page) on
Mon, Jul 7, 14 at 21:59

Hello All,

This is my first post as a member. I'm hoping you can give me some advice. We recently purchased a house that has a large lined pond with quite a few gold/koi fish from the previous owners. They have been able to make it through Michigan winters due to the depth of the pond. It's approximately 100 x 50' and ranges from a sloping shallow end to around 7' on the deep end. We have a fountain in the pond (I will post a picture if I can). We have been swimming on occasion in the pond, but I'm curious as to what you think. Right now, the water is very cloudy with lots of particles from the leaves and such on the bottom. I've been using Muck Away, EcoBoost, and Pond Clear for the past month and a half or so. I also did a heavy (too heavy) treatment of the nature's blue pond dye at the end of last summer. It's still blue. The liner edges are covered in particles that are churned up when you walk in and they are also slippery.

Is it ok to swim in the pond? What would you all recommend I do to keep the pond maintained and in swimming condition? How clear can/should I get the water? Should I drudge the dead leaves and such from the bottom? What do you recommend I use to do so? I'll take any advice as I'm new to this and want to make the pond as beautiful and functional as possible.

Follow-Up Postings:

RE: 100 x 50 large pond maintenance for swimming

As you've probably already gathered all the Muck Away, EcoBoost, bacteria products are complete scams.

Pond Clear has some use, but is mostly scam. For your size pond you would need about 800 lbs. That's 160 5lb bags, about $2240 per treatment, for 3 months of clear water (which I seriously doubt would happen). Kind of expensive and a lot of work.

Dye is effective in reducing algae growth. So you get dark blue instead of green. So to me there's not a lot of difference.

The fountain is purely decorative, it does almost nothing to do anything useful to the pond itself.

There are fish safe (kind of) oxidizer products that can burn up organic matter (not completely) but it would be very expensive and difficult to use. Chlorine is an oxidizer, and these other oxidizers work the same way. If you know about swimming pools oxidizers aren't magic. Filtering and vacuuming is still needed. So I wouldn't recommend oxidizers for your pond.

There are copper based algaecides which are commonly used in large bodies of water. It's cost effective because a copper molecule will attack an algae cell and when the algae cell breaks down the copper is released to go find another algae cell. Oxidizers work once and it's gone. The copper algaecides are deadly to fish in high enough doses, and probably not great for them at directed doses, but they are used in large fish ponds.

The idea with copper algaecides is to use just enough to keep algae down, but not so much that fish die. Needless to say it's tricky. Takes serious learning and care.

There are other algaecides too. All products will say something like "fish safe"...but that isn't exactly true. You want to read the MSDS that law requires sellers to provide and companies aren't allowed to lie on those. All the algaecides MSDS I've read have said they kill fish. "Fish safe" means the fish aren't killed outright. Long term effect isn't tested. I'm sure not saying you shouldn't use this or they're evil or anything like that. Just saying you should be informed.

I don't know the effect on humans. I assume swallowing water with algaecide is probably not good. But swallowing pond water isn't good either.

However, algaecides are not magic either. There will still been a lot of slime on surfaces and muck on the bottom. The bottom will have a greenish blue color when copper based algaecide is used.

There are people who will suggest all kinds of fixes, like bottom drains. They think a couple of drains will solve all your problems. But for your size it would take about 91 drains plus all the equipment needed to make these useful. The cost would be north of $200,000, maybe way north and probably more than $1,000 per month to operate. So solving this with equipment wouldn't make a lot of sense since you could build a brand new swimming pool for way less cost.

No matter what you do the sides and bottom will remain slippery. It's a bio film made by bacteria, a jelly like substance that the bacteria lives in to anchor itself. Even rough concrete becomes pretty slippery, but does give you some traction. You can put a thin, 1" or so, of concrete over the liner, or part, for walking on.

UV filters are used to kill algae that causes green water. For your size pond these would be very expensive to install and run, but they are 100% effective when sized, installed and maintained correctly.

As fish poo, leaves, etc get into the pond and decompose you do get a lot of little bits suspended in the water. There are filters to remove this stuff but that would be a serious amount of cash and maintenance. Removing the stuff before it decomposes too much is a better way to reduce the suspended stuff. It reduces the supply and over time the current suspended stuff will continue to decompose into smaller and smaller stuff until you can't see it.

There are lots of tools for lakes for removing junk from lakes, but most are for removing weeds. You could check them out, but you can't use anything than will damage the liner.

Another choice would be to vacuum. I designed such a vacuum called the Muck Mop, here are build instructions. It would be a big job to vacuum the entire pond, several days. But it could be used to just reduce organic matter. You'd need a boat.

Another vacuum choice would be to buy or rent a trash pump. Placed on the bottom and moved around this would pump stuff out of the pond alonf with water. However it very well may suck the liner into the pump which would not be good.

You can also scoop stuff using a leak rake. This can be very effective when there's a lot of stuff on the bottom, but you need a strong pole or be careful. I've bent the normal aluminum pole.

A seine net could get a lot of stuff, but wouldn't be fun.

There are web sites devoted to "natural pools" or "swimming ponds". Worth a read. Basically it just a question of whether you want to swim in such water. Ponds contain bacteria including the flesh eating bacteria, but this same bacteria exists in all soil too. It normally isn't a problem for humans. People have certainly swam in such water for a really long time, but there can be issues. To me, if you understand the risks and know what to look for to catch problems early the risk is greatly reduced.

One more thing on clearing the water...Should the water clear you're likely to get other kinds of algae that are more like plants. Something generally called string algae is one class. That can become a problem too. It's can be removed manually using different tools, but is a pain.

There are also "lake management" companies that can be hired to do pretty much anything you want given enough cash.

RE: 100 x 50 large pond maintenance for swimming


Wow. Thanks for the plethora of information! It sounds like my only option for swimming in clean(er) water is to drain the pond and put in a swimming pool! ha!

I will use up what i have as far as the pondclear and will not buy anymore...that was a waste of money.

RE: 100 x 50 large pond maintenance for swimming

Ponds change. Later on you might wish your pond was as clean as it is now.

RE: 100 x 50 large pond maintenance for swimming

I only have experience with ponds, but there the #1 remedy to get clean water is to have enough desirable plants that consume the nutrients that the algae don't have a chance to grow. My own small pond has so much submerged vallisneria and parrot's feather that there simply isn't enough left for algae to take a foothold. Before the vallisneria took over I had a bit of algae growth in spring and I would buy some water lettuce and water hyacinth to consume the nutrients, which worked well.

I've been researching "natural pools" for a while but haven't been able to find the time & energy to build one myself, but the principle is the same. If I were you, I'd dedicate 1/2 the pond to plants that consume nutrients and keep 1/2 to swim (or something like that). You would have to install a barrier to separate the areas and I'd put a jetty of some sort to allow you to get to the deeper swim area without slipping at the margins (where having plants is a better plan anyway). Given your climate, you'll have a bit of work each spring to re-establish plants and so you'll probably go through a phase where the algae leap ahead before they're reined in, but it ought to work.

A resource that I've found very good (but not all free) is (I have no affiliation with them but I did buy the ebook). The free stuff pretty much gives you the overall gist.

Good luck! The best is if you can view it as an experiment and work slowly at it.

RE: 100 x 50 large pond maintenance for swimming

It is a myth that plants can consume enough nutrients that algae can't grow. A green pond almost always has zero ammonia and nitrate while clear ponds often have way above 0 nitrate. This has been proven in many studies done over many years by Universities and the Department of Agriculture in many states related to fish farm ponds. And can be confirmed by anyone with a pond and a test kit.

Interestingly though I think Vallisneria is one of the plants currently being tested for producing a chemical (allelochemical) that kills single cell algae. We do know clear pond water is often toxic to green water algae, kills it on contact. I believe string algae is the normal producer of these allelochemicals, but Vallisneria could too. I wouldn't be surprised if most underwater plants do.

RE: 100 x 50 large pond maintenance for swimming

waterbug_guy, do you have any references to any of the studies?

RE: 100 x 50 large pond maintenance for swimming

Here are a couple, but there are 100's, maybe 1000's.

An Introduction to the Study of Algae by V. J. Chapman contains a lot of references.

U.S. Geological Survey, National Water Summary 1990-91, Hydrologic Events and Stream Water Quality

by A. Neba and P.D. Rose 2004

Compare that to zero studies showing plants can reduce nutrients to zero and starve algae to an almost complete absence. But to be fair the reason there are no studies on this is because it makes no sense to anyone with even a basic understanding of how plants work. It would be like trying to get grant money to prove the earth is flat.

The only cases where a green pond shows > 0 ammonia/nitrate is when that isn't the constraining factor. Like if farm fertilizer is entering the pond. But for most ponds macro nutrients ammonia/nitrate/phosphorus is the limiting factor.

A common way to control weeds (plants) in farm ponds is to add nutrients to try and start an algae bloom. That blocks light to the plants and slows their growth. This works because suspended algae is better at using these nutrients than the plants. In the contest of using nutrients it is suspended algae that is the winner, not the plants. There are studies that show this.

There have also been studies that show why humans create and believe such myths as plants starving algae. See work by Jennifer Whitson and others. There have been other studies that explain why people who believe these kinds of myths question any challenge to the myth but never question the myth itself. Very interesting stuff imo.

RE: 100 x 50 large pond maintenance for swimming

man, you really get worked up about this stuff! I asked a simple 1-line question for references and you act as if I was questioning your sanity...;-) Anyway, thanks for the references.

RE: 100 x 50 large pond maintenance for swimming

Mother nature is all about competition.
Oh, and by the way, I wouldn't swim in that pond.

RE: 100 x 50 large pond maintenance for swimming

man, you really get worked up about this stuff! I asked a simple 1-line question for references and you act as if I was questioning your sanity...;-) Anyway, thanks for the references.
Sorry I upset you. It is a forum...discussion...stuff like that. If you wanted a simple answer, some references, I suggest you try Google in the future. It really is pretty useful. Gives you just what you want without the discussion. A bit more work maybe than asking other people to do the search for you but it saves you being forced to read all the bah, bah, bah crap.

RE: 100 x 50 large pond maintenance for swimming

Useful information is brief & to the point.
The rest is just overflow waste!

RE: 100 x 50 large pond maintenance for swimming

It's an interesting concept. Not just asking for free advice, but also demanding it be in a certain form. Trouble is I don't much care to converse with such people so I don't really care what they want or demand. In general I've always found them to be very poor conversationalists.

I think some people may not understand the point of posting, at least for me. I don't post to help regular posters. They're not here to learn, teach, or have a conversation. I post because I like to think about ponds and to help guests. And questions give me something to research a little more each time, learn a little more. So I go on and on basically because I enjoy it. Sometimes I play Freecell, sometimes I post. I sure don't expect people to read it. Why a person would chose to read all that stuff they don't even care about...and then take the time to post a nasty response is beyond me. I assume it has something to do with self esteem.

Regular forum posters think my posts are directed at them, and therefore they think posts should be tailored to their tastes. I prefer to tailor posts to readers who who never post, the guests. In all forums if you look at the number of registered members online compared to guests it's always 10 or 20 times as many guests. Guests read my posts and often email me directly with questions. Which is always fine with me because I find these people much more open minded, secure in themselves so not as defensive, and more interested in actually improving their ponds than regular forum posters. Plus some of these guests even hire me to help them with their pond design so that's nice too. Regular forum posters are a big help with that too since many guests do see thru the nastiness and crap info normally posted in forums for what it is. Which is why I think so few guests ever register and post. Forums are pretty nasty places, always have been.

Sure hope that was useful.

RE: 100 x 50 large pond maintenance for swimming

Its not the forums that are nasty its the people on them who chose to be.

RE: 100 x 50 large pond maintenance for swimming

Forums are people. Without the people it's just unused software.

Each pond forum has a distinct personality driven by the handful of regular posters.

Within that group you have the forum royalty, normally just a few people. They post 20-100 times a day, have been a member forever. maybe even a forum monitor.

Then a bunch of minions who always agree with the royalty. Getting a kind word from royalty is nirvana.

Then a bunch of newbies that post for awhile and leave. Always a new flow of newbies at least in popular forums.

And then a sprinkling of trouble makers. You know, the real A wads. People like Dr Eric Johnson who post actual info and disagree with forum dogma. It makes the royalty look bad, exposes their lack of any actual knowledge about ponds. We can't have that! People don't spend 6-10 hours a day posting for 10 years to be dethroned by some johnny-come-lately.

First into the attack are the minions... repeating royalty dogma. What they lack in original thought they make up for with sheer numbers and personal insults, pummeling the invader with logic so relentless and mindless the invader can't type fast enough to refute it all. Each response the invader posts only adds to the word twisting and spinning the minions can use against the invader.

As the invader starts to tire from the avalanche of nonsense the royalty step in for the coup de grâce. The oh so standard logic used in all forums to shut someone up once and for all... "well I don't know about all that data and science stuff...but I fart in my pond once a day and my pond is great".

And with that the invader finally realizes that pond forums have nothing to do with ponds and everything to do with personal kingdoms. And Dr Eric Johnson stopped posting in forums.

Many troublemakers like Dr Eric Johnson have been shown the door by self-proclaimed "friendly" members over the years. It's a nasty ugly affair. After the invader has been purged the nice, friendly, members can go back to patting themselves on the back saying what a friendly little forum they have. At least until another troublemaker comes along who dares to question forum dogma.

I think nastiness may depend on perspective.

RE: 100 x 50 large pond maintenance for swimming

OMG, I'm a minion :-)

RE: 100 x 50 large pond maintenance for swimming

I'll call being a minion also. if thats ok?
King of a forum, who knew such aspirations existed!

RE: 100 x 50 large pond maintenance for swimming

Yeah, it is pretty sad.

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