we now have a small fish pond in the garden, its made with concrete and has plants and a fountain. my big problem is how do i control the algae growth .we were away for 8 nights and the water went from clean to pea soup.

There was an article on this a while ago...

cleaning-pond-water-t5646.html

Plus a couple of web sites for you (although I am unsure if a 'chemical option' is available in Udon...

http://faq.gardenweb.com/faq/lists/pond ... 24333.html

http://www.ubcbotanicalgarden.org/forum ... hp?t=15263

thanh you for the link, it did not come up on site search.two days ago i had a brainwave. having yet again seen allthe algae rise in the water when i tried to get it to the pump i decided to put the pump on a brick so it sits in the floating algae. first tries seem to get a lot of algae quickly

Hey You
I have been raising tropical fish & pond fish in and outside the house for many years while living in the US. Algae is always a difficult problem (especially outside) to tackle but it can be controlled. First of all remove the pond water and allow the concrete to dry (not easy at this time of year). Purchase some clear concrete sealer available at Global, Home Pro etc and coat the inside of the pond with 2 coats. Allow the sealer to throughly dry and then add water. Not your typical city tap water or what you draw from a well. The reason is that this water will probably contain a high amount of phospahtes & nitrates which algae thrive on. Fill the pond with bottled drinking water or get a water filter which will emiminate both these contaminants. Not all filters will remove these two contaminants so read the literature which comes with the filter first before purchasing.
Once the pond is filled and your filter is operating add lots of water plants (the more the better). It's next to impossible to overplant a pond so add as many plants as you can. Wait a several weeks before adding your fish to allow the plants to begin absorbing whatever phosphates and nitrates remain in the water and get themselves established. Do not add any plant fertilizer as this will probably contain nitrates and phosphates and have the reverse effect. Once the fish are added they will begin producing nitrates & phosphates in their waste and in whatever food is not consumed which hopefully the plants will absorb. Do not overfeed the fish as the food will turn into nitrates/phosphates and compound your problem. Your objective is to keep both nitrates and phosphates as low as possible.
Algae is definitely a real pain to deal with but with a little perseverence it can be controlled.
Best of luck with your pond.

Hey You

Just to add to the advice above, try to keep 1/3rd of the water surface clear of plants, unless you have good water circulation from a pump. Otherwise at night the plants use up all the oxygen and the fish will suffer.

fdimike2 wrote:Hey You
I have been raising tropical fish & pond fish in and outside the house for many years while living in the US. Algae is always a difficult problem (especially outside) to tackle but it can be controlled. First of all remove the pond water and allow the concrete to dry (not easy at this time of year). Purchase some clear concrete sealer available at Global, Home Pro etc and coat the inside of the pond with 2 coats. Allow the sealer to throughly dry and then add water. Not your typical city tap water or what you draw from a well. The reason is that this water will probably contain a high amount of phospahtes & nitrates which algae thrive on. Fill the pond with bottled drinking water or get a water filter which will emiminate both these contaminants. Not all filters will remove these two contaminants so read the literature which comes with the filter first before purchasing.
Once the pond is filled and your filter is operating add lots of water plants (the more the better). It's next to impossible to overplant a pond so add as many plants as you can. Wait a several weeks before adding your fish to allow the plants to begin absorbing whatever phosphates and nitrates remain in the water and get themselves established. Do not add any plant fertilizer as this will probably contain nitrates and phosphates and have the reverse effect. Once the fish are added they will begin producing nitrates & phosphates in their waste and in whatever food is not consumed which hopefully the plants will absorb. Do not overfeed the fish as the food will turn into nitrates/phosphates and compound your problem. Your objective is to keep both nitrates and phosphates as low as possible.
Algae is definitely a real pain to deal with but with a little perseverence it can be controlled.
Best of luck with your pond.

thanks , good post, very helpful

Other ways to get water with fewer nitrates: let the pond sit without adding water, or anything else for that matter until the algae clears up itself. I have bubbled air in the water, though I am not sure whether this actually helped. Eventually, if you don't add anything, the algae will clear itself up.Then, if you like, you can filter the water to remove the dead algae. This gives you water that can be used for the initial filling of the pond (or be done in the pond) BEFORE FISH ARE PLACED IN THE POND or in separate containers to be used to top off the pond to compensate for evaporation. I have done it both ways.

Rainwater, if you can collect it before it becomes contaminated is probably a pretty good source of water with which to fill or top off the pond.

Anecdote:
I had a wash tub on my front porch, with a thriving population of guppies, snails and water plants. It was down to about half full last month, when our housekeeper decided to top it off with city water. Within days, there was a huge algae bloom and all the fish were dead. I think this pretty much proves Fdimike2's point about the fertilizing effect.

I have a fountain in my garden and at first I had the same problem, then by a stoke of luck or a blinding revalation I am not sure which, I spoke to my local garden centre and for about 400 baht they came emtied it out, put in buffolo poo, then the stuff they plant flowers in. Then the water lilies over about 50% of the large fountain base which is about 6-7 feet across and about 2-3 feet deep.
Filled with water, two days later put in fish.
Fountain runs about 30 mins per day. No algae, fish a plenty, Guppies mostly and no problems. Must be the buffalo poo I think.

Rick

Excellent idea letting the water stand alone for a while. The algae will bloom and then die off once they have used up the nutrients and you will have algae free water to add to the pond. Just make sure to use an air pump to circulate the water a bit and keep it covered with a screen to prevent the mosquitos from using it as a hachery for their eggs.
Another point to remember about city water is that it contains some (how much I don't know) chlorine which will almost certainly kill the fish. I'm not sure how often and how much they add but according to the people at the water company they do add chlorine. Letting the water stand will also allow the chlorine to dissipate.

thank you all for the information,my biggest problem has been the girl friend. it was her idea to have the pool and everything had to be done now. of course within a couple of days of the fish going in the pool all interest in it vanished and i have to look after it. anything for a quiet life.