Topic: Green water and blanket weed

[newtona2]

I know this is probably the most standard question to ask - but just what IS the secret to getting rid of this stuff?

I have a 12000 litre pond, about 12 feet by 8 feet, and about 4 feet deep at its deepest. We have quite a lot of fish - following a population explosion 2 years ago when about 50-60 babies were produced and survived. I'd estimate we have about 80 fish in all, ranging from 1" right through the range up to about 7" or 8" for the bigger ones. ALl are just plain goldfish or shebunkin.

We have a number of plants (can't get lillies to survive, as the fish eat them), but probably not enough deeper water plants.

We have a Bioforce 9000 (includes a UV) and a large Titan pump - probably a filter capacity problem here, I guess.

Bottom line is the water is green, with very visible suspended particles, and we have blanketweed all around the edge of the pond. Both have been treated, with Greenaway and Blank-kit, with no noticeable success.

I am ssuming that we probably have to do several things:
1) Get more deep water plants
2) remove some of the fish
3) get a bigger filter.


Does this seem about right?

Is there any alternative? Could I just get a massive filter to improve the filtration, and keep all the fish? If so, what should I consider?

Help would be most appreciated.

Tony

[saddad]

I don't have fish and a much smaller pond but I find the duck weed and Lillies give enough shade to prevent Blanket weed / algae ever taking hold.
 ???

[teresa]

Blanket weed is in full growth now, due to the sunlight.
I manualy remove it with a garden cane and twiddle and collect it up. Never found a sutible chemical fish safe to do the job for me.
UV filters also dont help it seems to encourage it.
If you have a lot of fish you need a good pump to shift the water around also clean the filters out reguarly this should improve your water.
I have koi and they eat most of the plants barr a few so no water coverage.
I also have a still water feature ( an old bath) with plants and  duck weed in it no fish, no filter or pump, this gets no blanket weed and the water gets topped up when it rains or by tap not often and is clear and clean no smell so duck weed is good for something tadpoles love it.

[Anthony]

I suspect that most people on here combat BW using a series of methods - Floating plants like Water Hyacinth and Water Lettuce will reduce the nutrients in the water which make it go green - Alot of people also advocate the use of water cress (apparently the stuff that you can but at the local supermarket)  As mentioned lillies also help.  I think Hornwort is quite a good plant and apparently the fish tend to stay clear but again I'm not certain of this!

I would also suggest that you need a new UV bulb - I'm led to believe that they generally only last about a year - They still give off the flourecent glow but that's about it apparently!

Have you tried either Barley Straw or Extract of Barley Straw or Nishikoi Clay?  All claim to help and having used them myself will say that they do to a greater or lesser extent.  Finally why not try a grass carp - They grow very big, very quickly and again rumor has it that they like blanketweed.

Good Luck

Anthony

[newtona2]

Thanks all.

I have some Barley straw, which I'm going to put in today. Last one I used seemed to have little effect, but worth a go.

I'm going to the South of England show tomorrow, and will try to buy some Hornwort, and some Water Hyacinths and Water Lettuce - I had loads of these last year (and come to think of it, no blanket weed) but they all died off, so I guess I have to start again.

I think I'm also going to buy another filter box, and run it inline with my existing one, to see if that helps.

Finally, I'll have a word with our local garden centre people about the grass carp - to see if they recommend one.

Thanks again.

Tony

[Svengali]

I have developed about four isolated "islands" of billious green weed in an otherwise clear pond. It appears to be attached to plants that I want, so cannot just pull it out. It has a fermenting look to it. Can anyone suggest what it is, & how to deal with it?

[georgiesox]

I may be repeating but it's a hefty thread to read ;)


Replacing the bulb - The intensity of the UV in a UV bulb usually dies out within 6 months.

More cover - Floating plants like water soldiers are good for this. Water hyacynth are great to but are not frost hardy. Lillies do a fabulous job but are demanding... plus as you say they get eaten in your pond.

Algicides - Things like algofin and pond balance will kill off the algae but then you'll be left with sludge. You can use other products to break down this sludge. Some treatments will work in some pons and not others so it may be worth trying anther brand.

Barley straw - The most natural method - It only kicks in when the weathers warm and lasts for about 6 months. Make sure you get enough otherwise it won't make a difference at all. You can also get barley straw in a liquidised form and in a pellet form and these both get to work faster than an average bale of it.

Manual removal - You can by long poles with prongs on the end which you can use to get the blanket weed out with but it's a constant thing.


I hope this helps. G'luck :)

[Margaret]

To reply to Svengali first.Your green slimey weed is just another type of algae,and  is actually easier to eliminate than blanketweed.It will disappear as if by magic when you get enough plants  and weed growing that compete with the algae for food.It is mainly caused by very hot weather and a lot of sunshine.I get a bloom of the stuff in spring, just before the warm weather and my lilies take off.Difficult to remove but does no real damage,so just throw in some more fast growing weed,the wonderful hornwort i keep promoting is the best there is.

Newtone,you are like me in that you have a lot of fish,and the filters bear a heavy burden because of them with the extra waste being produced.I clean mine out very regularly,otherwise the water soon turns very green,sludgy and stale.Added to this however i have no problems with green water or blanketwed because for the last 2 years i have so much pond weed,hornwort and elodea,with plenty of lilies and the wonderful water fringe,introduced 2 years ago that is fast growing and very greedy on the old nitrates.

It is very easy to skimp on plants as you want to be able to see the fish and give them room to swim.I have struggled with algae problems,like everyone else does,for many years,even with 2 large ponds.But as each year the plants grow,multiply and really fill up the pond,i am having less and less problems and i think this really is the only answer.The larger the pond,the easier to control the problem,especially if you have the depth.

If you have a powerful UV bulb and keep replacing it you wll get the clean water but are then much more likely to get blanketweed.I turn mine off as often as poss which not only lets the pond get a little bit green,preventing too much sunlight causing the blanketweed to grow,but extends the life of the bulb also.It is a case of trial and error over many seasons and even after 16 years i am still learning,still making mistakes,but learning from them as well.This year i have, at the moment,12 lily flowers out on one pond and 8 on the other,and the leaves cover over two thirds of the pond.So all the hard work i put in,almost every day in the summer,pays dividends.They ARE hard work,especially with as many fish as i have!!

[grawrc]

Ours is 6x9feet approx by 3 feet deep at its deepest point. It has lots of fish and frogs - mainly goldfish type fish. It has water lillies, irises, marsh marigold and oxygenators.  plus a huge variety of swimming and flying insect life.It has no filter, pump, lights or any man-made assistance. It has never (touch wood) had blanket weed or excessive algae. We top it up occasionally from the mains. We have no idea why it is so healthy, but it is. Gets loads of sunshine but shade early morning to about midday?

[Svengali]

I have noticed that my "islands" of algae are slowly diminishing in the sun! I have ordered both Nymphoides pellata, and Hornwort, but the supplier you gave, Margaret, no longer seems to stock it. I ordered it from Aquatics Direct, who took the order a fortnight ago, have not yet delivered and have ignored all my follow-up emails asking for a delivery date. Shan't be using THEM again!
Now I have a sort of problem-in-reverse. When I dug my pond, I decided to go with a grey liner, to match the slates that I edged the pond with - and it looks awfull - I should have stuck with black, particularly as my water is so clear.
When I had my small pond in Oxford, built with a pre-formed liner, the liner was quickly covered with an algal growth, and I was hoping the same thing would happen to my grey liner, to help hide it - but nothing! Algae refuses to grow on it! There are no fish in my pond, though I will shortly introduce some minnows to keep down mosquito larvae, can anyone suggest how I can encourage algae to colonise my liner?

JeremyB

[Margaret]

Hi Jeremy.Is the liner you are trying to hide under the water or above it?If you have plants growing around the edge they will of course hide it to a degree,but if you have hard water the algae wil take hold to a degree ,but with soft water they won't.Difficult to know what to suggest.You can get a liner on a roll that has little bits of gravel size stones attached that does look good but i woild imagine it needs to be done at the time of installation.

Sorry to hear you are having problems getting your plants.You would have done better driving up here and me giving you bucketloads of this hornwort that is growing like mad.The Nymphoides has today decided to flower and looks great.

If you do want to find out more about the liner edging i will have scout around and find out more,so back in a mo.

Grawc,glad to hear your pond is doing well.Probably the depth is the biggest single reason why you don't have problems,coupled with the amount of plants but i should warn you that if the fish keep growing in numbers then sooner or later,without at least a pump,you may find they will struggle for enough oxygen,especially on hot muggy nights when the plants are giving out carbon dioxide by the ton and depleting the oxygen levels.

[Margaret]

Ok.

http://www.watergardening-direct.co.uk/acatalog/Stone_Faced_Pond_Liner_181.html   

There is also another one that is a bit wider.This is a great company.Just down the road from me, i have spent hundreds of pounds there and got so much good advice i don't know how i would have got by without them!!

[Svengali]

My water is certainly very soft. I have previously put in bicarbonate of soda - 11kg - but the effect doesn't last. I am going to add powdered limestone to see if that has more long term action.
My liner is mostly visible under water, down the sides. I know the pebble effect matting that you mention, but it looks bad where there is a crease.
What I will TRY to do is to plant some vigorous trailing plants in the (very sandy) soil beyond the slate edging, and see if I can train them to tumble over the slates & down into the pond. This will have the effect of hiding both the slates and the above-surface bits of liner. I don't have a clue what plants to use. Do you have any suggestions?

JeremyB

[Svengali]

Hurrah! my Nymphoids have arrived (Not from Aquatics Direct) but planting advice seems contradictory. Some say root them in baskets in order to control them, others say just float them, & leave them to their own devices.
What would you do ? - I have a large pond that I want to cover.
JeremyB

[libby]

hi, which ever way you choose, you a 50% chance of getting it right, i think ::)

[libby]

my mates bulb uv has been gone 5days he's screaming for help? not now, replaced his uv ::)

[Margaret]

Hi Jeremy.I started off with mine in a small pot.I now have several different ones,in several pots!!they root very easily.As yours is a nature pond,best to plant them in the soil/mud in the bottom of your pond.They send out roots on the stem,with fresh leaves as they reach for the top of the pond.In no time you will find the leaves will help cover the surface,and therefore hide your liner.

To rebalance the PH of the pond,use pond balance from interpet.i have used it on several occasions,very effective and a natural answer to soft or hard water.

The sandy soil would benefit from the addition of some ordinary garden soil or potting compost mixed in to grow plants round the edge or i fear they will not do too well.Around the back of mine i have  planted ,amongst the ferns,hostas,irises,lobelia, astilbes and kingcups ;brooklime,which  trails into the pond,and that rare beast..grass!!Water cress will also grow and cover the edges well.Hostas will also get so large that the leaves droop,but of course you must water everything really well,almost keeping them permanently damp,as most of the above plants are bog plants really.

[Svengali]

My hornwort came the day after my nymphoids, and I planted it in single bunches over the pond floor. Today I looked for it, & can't see it!
I have squillions of taddies that look as if they never intend to leave home - most still have no signs of legs yet. Could I simply have provided a taddy take-away?
JeremyB

[Margaret]

Jeremy,you don't plant hornwort.It doesn't have any roots and if you were to actually try and make it stay at the bottom of the pond in this heat,it would go all brown and yucky.You literally just throw it in.In summer it floats around at the top of the pond and grows like there is no tomorrow,but in winter it drops to the bottom and lies dormant until the warmer temperatures.Having said that i can't explain why you can't see it.I understand you have a very large pond and it could be a bit lost in there! It could  have floated up of its own accord and be somewhere mid way between the depths,i should imagine it will have a lot of growing to do.Don't worry, i have never known it to be nibbled by anything!

The tadpoles i should imagine would benefit by feeding them some fish flake to help them grow,it may be they are not geting enough nourishment.Plenty of time for them  to put on a spurt yet. :D

[djbrenton]

I decided to help two problems at once so I've introduced daphnia into my pond. It helps keep the water clear and also provides food for the tadpoles once they reach the carniverous stage.