Lots of trouble last year with green water. I bought a treatment from the local pond and garden place, and while it did clear the green water within a few days, the result was only temporary. By mid-summer the water was as green as ever, and the treatment really affected some of the plants. The water iris didn't bloom at all last year, and lots of the leaves turned yellow. Had I really thought this through, I'd have realized that anything that will kill off algae (like acid, which is what this treatment basically was) is likely to affect the aquatic plants. The bottle said "safe for fish and plants", but... Well, perhaps they meant that fish and plants would just suffer a lot, but wouldn't actually die. Anyway, I came to terms with the green water (it is loaded with life, after all, and fun to look at under a microscope) and decided that I would Never Tamper With Nature Again. Now it's one year on, and what do you know, the aquatic plants are doing their job, and the water is pretty clear!

So that was last year. This year, over the past few months, I've noticed the string algae (blanket weed?)seems to be really taking off. It wasn't a problem at all last year, just a couple of small clumps near the irises. Nothing I couldn't handle with the old twirly stick routine. This year, however, as the oxygenating plants have really spread out near the center of the pond, the string algea has been keeping pace with it, forming a thick, green mat through the plants, and even clinging to the sides of the pond liner. Sadly, this is where the frogs decided to spawn this year.

Right before the last cold snap, the tads made their appearance. I could see they were way too close to the surface of the water, and the blanket weed was keeping them right where they'd been layed. I thought about trying to scoop some of them up, and plonk them into the shallows, where they'd be warmer, and then remembered that I had promised myself that I would Never Tamper With Nature Again. So I let them stay where they were, and of course the cold snap killed about 97% of the little guys. Okay, it was bad enough to lose all the future frogs, but the MESS they left behind in the pond really added insult to injury. Millions of little comma-shaped corpses, and the floaty egg sac stuff, all mixed in with blanket weed, and a winter's detritus - I'm not squeemish, but YUCK! I've cleared some of the blanket weed out today, but there's just so much of it, and no matter how careful I am, I wind up taking out some of the good aquatic plants with it. Heck, I even twirly-sticked a newt in with the string algae this morning! Poor little guy didn't seem any the worse for it, thankfully.

So where I go from here depends on your advice. How do I get rid of the blanket weed? Do I want to? Will it clear up on its own? What sort of thing competes with it for nutrients, and where can I get some?! Also, I have a lot of sludge at the bottom now. What about those pond vacs I see all over the place. Are they any good? I see a lot of string algae on the sides and bottom of the pond, and am wodering will a vac work to clear it? Will disturbing the bottom of the pond to suck the sludge out affect the lilies and irises? The lilies are in pots, but the irises are not.

Lots and lots of questions, and to offer answers you probably need to know that my pond is very small, about 7 x 11 feet, and only 3-1/2 feet at the deepest. I have a small pump that feeds a trickle of water over some rocks - not a "water fall" per se, just enough to hear the sound of trickling water. I have no filter, and no plans for one. This is a wildlife pond, of approximately 1200 gallons, and there are 10 small goldfish in it, and several "mystery fish" as well. (Originally there were two, gleaned from a friend's pond, but they spawned the first year, and now there are seven. We still have no idea what they are.)

Any and all replies gratefully received. Thanks, and howdy!

Brenda

I manualy removed the worst of the algae which was like winding spaghetti onto a fork, it just kept on pulling out. I remember last year all the tadpoles demolished alot of the algae stuck to the sides of the liner and made a right good job of it, I think there is good nutrients in it for them. I know aquariums have a fish called 'algae eaters' but I do not know if they can be for ponds, I would think they may be tropical so obviously not, maybe someone else will know more about this.

As for removing the green water...from what I have learnt from this site you will not get anywhere near the results of clear water naturaly, than you would using a uv light. The water would have to be about 80% in the shade for most of the day for starters and have the right balance of plants. Even then. you will not get the 'crystal' clear water that alot of these uv filter manufacturers GUARANTEE with their products.

The second year of my pond I had loads of blanket weed. The third year I got the attack of the yellow globules and a little blanket weed (prefer the blanket weed). This year the water is getting greenish but not a lot of blanket weed and no globules either (yet, but I'm on the lookout). So it might be about pond maturity and balances too. I have also made sure that the barley straw is in, which seems to make some difference.

I have read about UV filters, but as my pond is in full sun until late afternoon, they probably wouldn't work for me. I positioned my pond there on purpose, actually, as I really love lilies, and I wanted to created the most favorable conditions for flowering. I knew that full sun also meant lots of algae, but for me the trade off is worth it. Last year I had six flowers, in various stages of opening, on the pond at once, and by moonlight the sight was just magical.

Dampflippers, thanks for the suggestions. I feed the fish about twice a week during the summer, not at all during the winter. Truth is, I really like feeding them, as it makes them love me. (And who doesn't like to be worshipped and adored? Even if only by a small school of fish!) But I really will stop, as I know it makes the water nitrogen rich.

Tell me more about this daphnia. I've never heard of it.

As for the remaining blanket weed, I'm considering "borrowing" some tads from a neighbor's pond - with permission, naturally - as there's plenty in my pond for them to eat. The other pond in question here is about a quarter mile up the lane. When the borrowed tads become frogs, will they go back to the neighbor's pond, do you think?

I must say dampflippers, your ponds sound lovely. Any luck in bat detecting? If I go out at the right time just after dusk, some bats flutter by for about 5 minutes before heading off. The roost in the nearby park and we must be one of their scheduled stops. Its odd because you kind of sense them before you are able to focus on them. Once you see them, there off!

Anyway UKYankee, if you transplant spawn you should be fine, its tadpoles and frogs you want to leave well where they are. Best of luck with the next batch.

I rebuilt my pond last year, so its less than a year old now. It's roughly the same size as yours. Blanket weed is a big problem right now... previously I used barley straw with great success, but this year it seems to have no effect. Or perhaps the blanket weed would be even worse without it. I'm not too worried though - I suspect that my pond has not achieved a natural balance yet. Probably too many nutrients from the soil with all the new plants I added. It will probably take another couple of years before it settles down properly. I'm currently pulling out great swathes of it by hand regularly, but once the tadpoles start hatching I'll probably just leave it.

As for green water, you can try a UV unit, but personally I have had no success with that method. I just got a thick suspension of dead algae instead of a thick suspension of live algae. Maybe I didn't get the right size of filter or UV unit, or the flow rate from my pump was too high or too low. Whatever, it had no effect on water clarity and just increased my electricity bill. So, when I rebuilt my pond, I went with a big DIY filter instead, based on the Skippy filter. Do a web search and you'll find Skippy's site whch has details. It's a "natural" solution, which may suit your philosophy. Takes a lot of space though (compared to commercial filters).

Other things to counter green water is to have plenty of plants, especially a) a good coverage of floating ones (or ones with sperading leaves/pads), which will provide shade and therefore reduce algae growth and b) ones which grow rapidly and use up nutrients fast eg. watercress. Again these are "natural" solutions. I buy bunches of organic watercress from the supermarket, and throw it in the open top of my filter where it grows like mad. I buy lots of floating Water Lettuce and Water Hyacinth each year (they die in Winter), and the lily pads help as well. I have water soldiers too. I've had duckweed in the past which worked great, but was so rampant that I had to scoop out a bucket load almost daily. My current fish love to eat duckweed though, so that doesn't work any more (same result with azolla :-P)

So far, floating plants and the new filter have kept the water clear, but the real test is yet to come this Spring and Summer when the temperatures rise and we get more sunlight.

Well, whatever you do, good luck!

ps Sean is an expert.