11 replies to this topic

[Mintox]

Just came back from helping my friend clean his pond. The water is green and you can hardly see the fish. This is a roughly 9000l pond with a 15000l/h pump to a filter. The pump output is split with a T-junction and the returning water falls down an algae covered waterfall.

Today I took the return flow from the filter and made it go straight into the pond, not the algae filled rocks. The other side of the T-junction from the pump is circulating the water instead of making its way down the algae water falls.

My question here is it safe for the koi to be in a pond which has this good circulation? I am a bit worried because the large orange female did a bit of a jump. Not very high and landing safely.

I'm hoping the new pond setup will help clear up the water so we don't have to use the algaecide. There is a UV light in the filter, not doing a great job as of lately.

Thanks for any pond info and I hope this thread is ok in this forum.

[SynoAngel]

Hi mate,

I'm assuming you've had this filter running with the same UV globe for a year or more? Do you know the UV globes need replacing every year?

Pretty sure thats your problem,

Daniel

[Mintox]

Thanks for the response Daniel.

Last month we took apart the UV light housing and I guess the light wasn't that bright. Ill have to check on when we first turned the filter on, knowing how time flies it has probably been more then a year ago. I just hope they aren't too hard to replace.

Thanks Peter

[SynoAngel]

Hi Peter,

Not hard, just expensive. Usually around the $50-70 mark pending the wattage of the globe.

You will find if the globe is working the globe will not have anything growing on it (UV kills plants and living things). The globe should be displaying a bright blue colour (You get a headache if you look at a new one, dont try it).

Regards

Daniel

[Adam]

Is there any reason you stopped using the water fall? It will contribute to increasing and decreasing in summer and winter respectively. The macro algae on the rocks want be contributing to the bloom of microalgae. Normally the reason koi ponds become green is that they continuely turn the sediment over prevent the locking up of nutrients in the anerobic sediment layer below the thing aerobic layer.

If I was you I would remove the organic nutrient rich sediment on a regular basis; shade the pond; increase the mechanical and bioligical filtration; and increase the trophic niches in the pond.

Typically you will need to remove the sediment once or twice per year. Do it slowly and remove it as systamatically as you can with out stirring it up int a bloom. Use the water and sediment on plants in the garden.

Use plants or shade sails to limit the amount of light and intensity that hits the water surface. This will limit another factor that makes the phytoplankton bloom.

Change the filtration system to assist in processing the nutrients that result from the koi feed that you are adding. Also by changing the mechanical filtration you can 1) remove the chunking nutrient solids (food, faceas, etc) and depending on what you do you can also remove photoplankton and/or damage before it enters the pond.

Add other fish, crustaceans and plants to provide additional users of trophic levels in the pond. This is difficult but possible.

Through all of this you are trying to increase the biological stability of the pond and limit the factors that contribute to grwoth. It is likely that you will still get minor blooms that lag behind the changes in temperature of spring and autumn.

Good luck you aren't fighting a losing battle. It is something that you can control once you establish the right blance.

Adam

[Mintox]

Thanks for the wealth of information Adam.

To answer your first question. I decided to get rid of the waterfall route as my friend was scrubbing the green slime off the rocks against my instructions. I'm not sure if this contributed to the problem, however I wanted to stay on the safe side and stop him from doing this.

I have told my friend that putting a shade cloth over the pond will eliminate a large portion of the green water problem. However I'm not sure if he'll heed my advice.

The water in the pond was of decent clarity for quite a few months. Many factors such as introduction of lily pads (including fertilizer tablets inserted into soil) and foreign plants from some river may have made things worse. You mention this build up of sediment contributes to the problem, perhaps it was this. Another problem may be the UV light as already speculated. We forgot to turn it on when we first started the pond and we got pea soup, within a few days the UV light had cleared it up.

My friend has been bugging me about using algaecide. This is gonna create a lot of breaking down matter and the bottle warns about the low oxygen levels created by this. This was one of the reasons I decided to add more circulation to the pond. What are your views on algaecide?

Is there special extra fine nets used to take out this sediment? My friend's neighbour recommended the algaecide and to scoop it out with a net.

This would be a lot easier to tackle if it was in my backyard, since it's in my friends it's often hard to convince him to do the work.

Thanks Peter

[SynoAngel]

Hi Peter,

There is a product called AlgaeFix, made by Pondcare I think. You dose the pond at the rate of 5ml per 200Litres every 3 days until the algae is undercontrol. I have found this product (from working in the retail industry) to be really effective and about 80% of the customers had there problem fixed within a few weeks (usually). You may find however that you (or your friend) will need to clean your filter almost daily until the majority of the algae has been removed from the pond. Experiences has shown me that your filter WILL block up when using this treatment.

Personally I would replace the UV globe then start this treatment for ultimate results.

Regards

Daniel

[Mintox]

Thanks for the response Daniel.

I'm not 100% sure but I believe this is the algaecide we picked up from the lfs. I'll start treating the pond some time next week when my friend said we'll get the new UV light. My lazy friend may take some convincing to clean the filter every day during treatment, may have to borrow another set of hands as he may not be willing after a days work.

Would it be a good idea to leave the pond circulation as is for the treatment?

Thanks again,

Peter.

[SynoAngel]

Hi Peter,

I would hook up as much filtration as possible, you will need it (without taking cash out of your pocket). Your filter will block up and the flow will reduce but this is only temporary while the algae dies.

Daniel

[johnnie7au]

This might help...


http://www.perthcich...h...opic&t=7613

[Adam]

I personally don't like using algacides a great deal. My experience is that they are hit and miss. It is better to tackle the problem than put a band aid on it.

By changing the type of mechanic filtration that is occuring you will filter out the solids.

Good luck. There are many ways to skin the cat and personal preferance and experience usually play the major deciding role.

It took 9 months for my parents pond system to settle down and obtain the water clarity that they wanted. It has now been stable with periodic maintenance for 8 years.

Adam

[Mintox]

Well, there was some good news in that the water cleared up a bit. However the pump had something caught in it and the filter had no water pumped into it over night.

My friend agreed to a shade cloth (hope he keeps his word) and we will start the algaecide process sometime next week. We're gonna try scoop up as much sediment from the bottom and hopefully it will start to clear up.

I have taken the DIY filter into consideration and thanks for the link.

Thanks Peter