Blanket Weed

Submitted by broonaldo on Tue, 24/07/2007 - 9:08pm.

I am new to pond keeping and have contructed my pond in an open site. The pond is about 9ft by 6ft and one metre deep, it contains about 500 galls. There are two lilies and several marginals in the pond together with hornwort and about 40 inches of gold fish.
The water in the body of the pond is clear, however on the preformed waterfall, blanket weed is taking over. Some time ago I treated the pond with a product called Pond Balance. I did this because the water was slightly green and was showing very slight signs of a few strands of the weed. This seems to have had the desired effect on the main body of the pond but not on the waterfall There is a UV light incorporated in the filter. The water fall is from Rockways and is made of concrete it has a wide spread and is consequently quite shallow although not slow. I could increase the flow if this would help
Has anybody any solutions or suggestions?

‹ Silt?
»

Blanket weed

Submitted by Peter May on Thu, 26/07/2007 - 4:04pm.

There is nothing like a high pH that gives blanket weed the edge over the other plants. So anything like concrete products or limestone in or around the pond give it a boost. Phosphates coming from soil runnoff. the heat absorbed by the thin layer of water in a stream is also nirvana for 'cotton wool' algae. Rockways are the very best in preformed waterways, but some designs are given strength and weight with concrete which can leach the pond. Even if the top surface is coated it can leach in from underneath.
With 40inches of fish you need lots of plants everywhere to try to starve out the algae. Also lilies in the pond for pool cover.
If there is even one koi in there, then you must establish some plants remotely in a 'veggie filter'- a minisort of reed bed.

Your filter system will not pick up blanket weed, it only gives single celled algae a hard time, so you need an alagaecide that will break up blanket weed. These are easily available and are ecologically sound. (check that it is on the bottle). Once the blanket weed is broken up a good pump and filtration system can easily take it up.

If you already have a good cross section of marginals, oxygenators and deep water plants established you can tip the balance in your favour by using one of the fairly new bacterial algae inhibitors. These creat microbial conditions that are not favourable to primitive single celled plants and favout the higher plants. These really do work permanently if the conditions are right and one everyone is talking about at the moment that is particularly good is the Cloverleaf product - whichhas briefly slipped my mind, but is mentioned elsewhere in this forum.


»

Blanket Weed

Submitted by broonaldo on Thu, 02/08/2007 - 8:35pm.

Many thanks for the detailed reply. The Cloverleaf product to which you refer in your answer I think is called Blanket Answer. After reading the blurb it seems to work in the same way as Pond Balance which I have tried, only for a couple of months admittedly and it has kept my pond clear of the dreaded weed but not the cascade. I think I will go for an algaecide as you suggest and see if that has any effect.
None of the products I have looked at say whether or not to leave the UV light on whilst treating the pond. Is this important?

Regards Colin.

»

Blanket weed

Submitted by Peter May on Thu, 02/08/2007 - 10:43pm.

High pond water pH,Phosphates leaching in from soil and surrounding grassy areas, also the heating effect of a thin film of water that is a stream are all great boosts for the scourge of blaket weed. Its one advantage is that it discourages other algae from being a problem.
You can either plant out the stream in order to make it a bit of a veggie filter or you can build up discouraging microflora with one of the newish bacterial algaecides. Blankeet Answer by Cloverleaf seems to be the flavour of the month at the moment. Its expensive but it works and for a long time too.
Ultimately more plants and the microflora they encourage are the permanent answer. If you've got koi, use plants remotely in a veggie style filter.


»