It's going to be dependant on what you want the pump to do. A fountain yes, a waterfall or stream, not really. Any pond advice you need, give me a message, if I don't know. Other people here will..

My pond manages without any water circulation. Its not essential if you get the balance right.

If you intend not to stock any fish in it you don't need a pump. Solar pumps are very weak and are only functional to power small water features. I have four ponds with electric pump water circulation and one pond with no pump in which I grow lotus. For still water ponds it is best to flood out one quarter of the water volume every other day or week depending on the time of the year to prevent water stagnation. Water stagnation will promote chemical byproducts from bacteria which can burn the roots of water plants (that rotten egg smell) and also will encourage mosquito growth which with the advent of the Zika Virus in the USA is a very serious development.

Thank you all so much for your advice. The little pond I have certainly suffered this year from water stagnation and I'm sure was a breeding place for mosquitos. The first one I made here was fine but a tree root pierced the pond lining so now it's a bog garden. I'll start again from scratch bearing in mind your suggestions. I don't want to have any fish, just plants. Thanks again.

Hi Ginellie. My first small pond had electric pump (mains supply) and a UV filter. Complete waste of time and money...it never helped at all. The electric pump was useful as it meant I could have water pouring from a nice urn in tothe pond. But it didnt help with algae at all. My last two ponds have had no electricity. I did try solar, but it was useless to be honest. I think you just need loads of oxygenators and perhaps flooding helps...I do occasionally do that. But try to provide shade using tall plants, as direct sun is a real problem in summer. Good luck. A garden without a pond is a barren place (well, not really, but a pond is such an asset for wildlife).

You will always have algae (string type) in your pond. It is at its heaviest growth in spring and fall and believe me it is a daily chore to keep the pump intakes clear of string algae. It gets much less when the floating pond plants such as water lettuce, water hyacinth etc become available in late spring to be placed in the pond. They are very fast growers (a purchase of five plants will get you five hundred in three months...no kidding) and suck all the nutrients out of the water as well as shade it and within a month or two the pond will have a minimal amount of algae and clear water. Of course from time to time overgrowth of these floaters must be removed so 1/3 of the pond has a clear water table for gas exchange. I place the removed ones into the compost pile so nothing is wasted.

On flooding, it can happen that putting in fresh tapwater can add a fresh supply of the minerals that encourage the algae so you just end up having to keep doing it. If you are looking for floaters to shade the water before you get enough cover from lily leaves Frogbit is useful, has pretty little white flowers and spreads quickly.
When you scoop out the surplus from time to time leave them in a heap on the edge of the water for a while to allow time for any little water creatures to escape back into the pond.

Many thanks again for all your advice. It seems that I should really concentrate on having the correct plants in the pond and forget about the solar pump. I didn't realise full sun would be a problem when I chose the pond site. Having said that, my old pond-now bog garden- had very clear water though it is in the shade most of the time. I've cleared most of whatever was growing in the stagnant pond, including taking out all the massive irises, but thought I would leave it as it is until after the frogs have visited in March and then re do the whole thing.

I forgot to mention that we do have in the USA a mosquito larvacide that is known generically as mosquito dunks that will eliminate mosquito breeding in your pond. It's MSDS (material safety data sheet) shows it to be absolutely harmless to the pond. So if you cannot flush your pond frequently this is the thing to use if it is available in the UK.

Ginellie, I am joining in on this thread as our small pond was emptied out yesterday, a revolting job for OH and I, but we got to the bottom of the pre-formed pond base. Found 8 frogs lurking in the sludge!

Now, it has been re-filled with rain water, one electric fountain put back in the centre and some Cabomba and Elodea Crispa, oxygenating plants, obtained through Freecycle as the aquatics shop are not selling them until March/April.

Will the water remain clear with those plants in, or should I add more?

Not this time of year since the light is getting shorter and the water colder. Next year place floaters into your pond and with a little patience they will do their job. Also, frogs love to overwinter in muck and I always leave a layer in the ponds for them. String algae and free floating algae will not harm your pond the only problem is when the string algae gets so thick that when it rises to the top in the daytime it covers the water surface so heavily that proper gas exchange is inhibited and that green carpet superheats the water underneath when the sun shines on it.

Thanks Loosestrife, pity we cleaned it out so thoroughly then!

Such a lot of really useful information. I'm just about to see if the mosquito larvacide is available here Loosestrife. It sounds perfect. I'm also going to have a look at other Goy members' ponds for some inspiration.

That's great and thank you. The final thing to remember is that your pond must never be as clean as your bathtub. The basic vitality of any artificial pond begins in a membrane which coats the surfaces of the pond this is called a "biofilm" and it is composed of microscopic plants and animals which are the ground floor of your ponds food chain and water conditioning. In fact scientists are beginning to regard certain types of biofilm as a living organism in its own right. You might like to have a look at my blog of July 30 2016 titled " World within Worlds" to see a few of the inhabitants which are in not only my ponds but everyone else's too and they provide the beginnings a food source for all other life in your ponds.