Topic: UV lamp explanation

[Mrs Ava]

Pond experts, could you explain in very simple terms please, what a uv filter thingy is, how it works, and what benefit it would be to our little pond.

Pond is lovely, fish all thriving, number one daughter been in once - today, but it is good and green and altho we see the fishes at feeding time, that is about it.  A friend suggested a bag of water fleas, she reakoned the pond would be clear as a bell within a day!  Is this true??

Yours pondly,

EJ!  ;D

[Margaret]

Hi Emma.oh the joys of green water!! The tremendous sun we have had lately makes it worse.The trouble is that although you have a pump,you would not,i would think,want a box filter ,even half buried ,next to your pond.You can only set up a UV lamp inside such a filter,as the single cell algae it destroys that is responsible for the green water,has to be trapped inside the filter box,and cleaned regularly,to prevent it returning to the pond.You are getting into the realms of fish keeping on a grander scale here.

The only natural answer is to give the pond more shade,either with surface plants,such as duckweed or water lilies,or plant some shady plants to overhang the pond.The fact that you also feed the fish only adds to the problem,as the nitrates caused by the fish waste feed the algae.It is all a case of getting a balance,and as the fish grow,it will get worse.It may clear in the winter,with less sun and when you are not feeding the fish,but only a truly ,amphibian only ,pond will be clear of green water and blanketweed,because you can have a lot more plants in and no fish waste.

[Mrs Ava]

Thanks for that Margaret, at least we now know.  What about the pond fleas - was that info from my chum fact or fiction?

Also, number one son just knocked a plant over in the pond, so when I retrieved it to put it back on the marginal shelf, I felt the bottom of the pond, and there is a thickish layer of very smelly grey slimey gooooo.  Should I try and syphon some of this away, or scoop it....or is that just part of the ponds balance, and I should leave well alone?

[ava_banana]

Just another quickie. ::)

Is this sort of thing suitable?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=57230&item=4317707992&rd=1

(it is an ebay link to a uv pond filter)..........

....ta for your help.......... ;D

[Margaret]

Sorry Emma forgot about the water fleas (daphnia)question.No;doubt that will work,they won't have time to consume much algae before they get consumed themselves by the fish  ;D

The grey slimey goo you speak of is annoying,but even I get it when my filter needs cleaning.However it is never smelly.It usually occurs after a few years of having a pond,not a few months.As you have fish,but no filter,there is nothing filtering this and yes it could be a problem.I gather all your plants are in pots?Do you have anything washing into your pond when it rains? i would net this out as much as poss,or syphon it out.Doesn't matter if the pond goes murky,it will settle.As you have frogs they will constantly stir this up,and that is one of the reasons your pond water is green.There are not enough plants to use up the excess minerals and nitrates,as I explained.

The soil you put in the pots,was it aquatic,and have you got plenty of gravel on the top,to prevent it from spilling out?When you do the clean up,put all you get out into a shallow bowl,so that you can rescue any insect life you find.

I am now going to look at the link ava gave me.

[Margaret]

The pondmate is similar to the green genie that i have.All filters and UV combis work the same.You need to have a powerful  enough pump, what do you have?And how many gallons does your pond hold?you will also need more in the way of pipework than you have at present,though easy enough to hide it.I would say it is a good investment,mainly for the health of your fish.

However I would not buy from the internet without actually going to an aquatic centre and having a look,and  a chat with an expert.There you can get the right equipment,and see for yourself just what it will entail.

[Margaret]

also.........
have a look at www.watergardening-direct.co.uk    they have lots of products and lots of helpful advice and tips.

[tedd]

From experience the only cure we have found for green water is a pump that will pump solids and agae and a filter with a UV lamp.

The filter box can be anywhere in the garden provided it is higher than the pond. The pump sits at the bottom of the pod and pumps the water and some sludge up into the filter. You then lift the element box out or dismantle it to clean periodically.

Our present pump is a Titan 8000 (£140), the pond is 6m X 4m and 1.5m deep in the middle with shelves. At the moment the pump is running 24 hours and we still get some algae in the pond and stream.

This pump is 3 year old and has blocked once this year. Our two earlier pumps would block with weed weekly and need dismantling.

I am rinsing the filter elements 2X weekly in rainwater which is then used as liquid feed for the plants. The filter is a Fish Mate with a 25 watt UV lamp. It has a lift out basket that hold the foam filters. Our earlier filter box had to be cleaned in situ which meant kneeling in mud and dismantling the assembly.

[ava_banana]

Thanks for your replies and advice.

Our Pond is not huge, it slopes down to around 2 feet deep in the deep bits, with shelves, and is around 11 ft by 5 ft but we don't know how much water is in it ( ??? yes, we know we should have measured it when we put it in ::)) anyone got a rough calculation.

The pond pump is a Hozelock Cascade 1000 (fountain type pump) (I think, again, I should have had a look before I put it in the pond, I will have a look at the weekend).

Pipework and disguising the filter isn't a problem as there are lots of plants and a couple of features around which will hide them.

We do have a very limited budget for this, so I will keep an eye on the local rag for "cast-offs".

What rate pump will we need for a suitable uv filter?

The pond doesn't get a huge amount of sun, and the plant cover is around 40 per cent.

[Margaret]

Hi Ava.The calculation is as follows   length x width x average depth x 6.24. this will give you approximate galls.i have taken your average depth as 1.75ft which gives you about 600 galls.You are supposed to turn over the volume of your pond through a filter in about  2 hours.Your pump,if you disable the fountain part( you may already do so)and have the total flow through the filter,turns over only about 175 galls per hour.

You will get away with it while you have small fish,but in the future you may want to upgrade,as the lesser the flow,the more ineffective the UV and the filtration.But you will be ok for now.

I am a great fan of the green genie filter/UV.I have one on each pond.You would need a green genie 3000,cost through watergardening direct is £56 but there would be postage.however,armed with these figures you could look around at other sites,or local places and see what else is out there.once you have got one up and running,and the algae cleared,you can turn off the UV part over the winter to save the bulb.I always leave the pump running to prevent the whole area freezing over.

[ava_banana]

Thanks very much for the helpful answers.......this weekend we will mainly be:

removing sludge.....

and saving for a filter  ;D

[aquilegia]

Get yourself some watercress. My pond has really cleared up since I put mine in.

I bought a packet from the supermarket (I looked round for some that already had a few roots on it). Then bunged it in a glass of water on my window sill, taking care to remove any leaves that went under the water. I lost a few, but most grew lovely long roots. Then I chucked the lot in the pond.

It looks a bit ropey and I wouldn't want to eat it, but it seems to be doing the job. Oh and this is in still water too.

[Margaret]

Glad to hear it's working Aqui.Mine is doing a grand job at the mo.At the end of last years lot i planted it up round the nature pond.It survived the winter and came up bigger and stronger than ever.So this year I have pulled it up,a bit at a time ,washed off the soil and put it back into the fish pond.There's value for you!!

Better still if you have a waterfall or stream,so yes,your suggestion to Ava is a good one.

You are getting the hang of this pond lark  ;D