How to Control All Forms of Pond Algae... Mo Magic Involved

I've written many times about pond algae problems and solutions. The problem of suspended algae causing murky water is the most encountered pond keeping problem.

There is a great deal of myth surrounding pond algae and it is a very lucrative business for manufacturers of "algae killers" since the products they sell, assuming they work at all, have to be replenished at very frequent intervals and this becomes costly as well as being a hassle.

I was prompted to write about pond algae solutions again after getting this question from Paul...

Paul's Question

I want to thank you for the prompt reply on the sludge. Because of the winter I have a lot of sludge and algae.

I had installed a UV filter to kill the algae. I know one of my problems is I stopped using the UV filter. I bought a product called POND MAGICIAN and the instructions say the UV light will kill off the living beneficial micro-organisms that are in the product and that multiply in the pond. This product is manufactured by Effective Environmental Services, Lake View Terrace, Ca 91342

I went to this product because a lot of the products are for Koi or plants but not both and I needed a dual purpose product. I am perplexed in how to get rid of a lot of the algae - I know some is good but I am past the some at this point.

Right now I have just been able to get my pump circulating the water because during the ice storm that hit Kentucky, we lost power for 4 days and my hose for circulating the water had frozen because of how cold it got - the ice in places was about 2" thick. Today the fish have become more active than they have been in about 2 weeks.

Thanks:

Paul Ford

My initial reply...

Paul, Hi

There is no UV clarifier for ponds on the market anywhere that will kill bacteria to any significant extent. The bacteria are also not circulating in the water… they are fixed to all pond and filter surfaces

UV is certainly used in the food and pharmaceutical industries for sterilization and disinfection purposes but these are much more highly engineered units and require much slower flow rates that any pond UV.

If your pond is murky because of algae there are 3 possibilities

The UV is not big enough in terms of wattage

The lamp needs changing.

The quartz tube inside the UV needs cleaning

An UV will not kill any type of algae that does NOT flow through the UV

Regards, Tony

Paul replied...

Thanks for your reply-

In the POND MAGICIAN TROUBLSHOOTING TIPS

The last paragraph states...

"One last thing is the use of UV filters will also kill off any beneficial microorganisms. They are usually recommended to control algae but will negate any positive results of Pond Magician". The product is an organic product and is suppose to have living microorganism multiply in the pond to help control the growth of algae.

I understand that if the flow rate thru a UV filter will slow down the purpose of a UV filter. The last paragraph of the trouble shooting guide caused me to disconnect the ac cord for the unit.

I am really confused now.

Thanks:

Paul

Let me try to remove the confusion and here's what my reply to Paul was...

Paul… What I said previously is correct.

Pond bacteria do not swim in the water… they reside on substrates such as rocks, pond debris, bilofilter media etc. Some may get circulated but these are a tiny fraction of what's in the complete filter system so even if a few are killed by the UV light the impact is negligible.

As such the vast majority of beneficial bacteria are not exposed to UV so they cannot be killed by the UV which has water circulating through it.

Bacteria are constantly dying and regenerating in a pond system.

UV in industrial food applications is to make sure anything undesirable that MIGHT be present is killed and this includes any pathogenic bacteria that might be present as well as water borne viruses..

Such a product is called a STERILIZER … people do not use STERILIZERS in ponds they use CLARIFIERS (ie to clarify or clear the water). A CLARIFIER specification is very low compared to a STERILIZER specification

I don't know anything about the composition of POND MAGICIAN.  From what you tell me they state the product is an organic chemical and in this case it is quite possible that the UV might break down the organic CHEMICAL compounds dissolved in water. By the way any product alluding to Magic has no place in a pond environment since magic is not an ingredient for success.

The UV CLARIFIER will not kill MICROBES.

The correct solution for suspended algae in a fish pond is to install a properly sized UV light. This system works all the time every time so long as it is sized correctly and so long as the maintenance required is carried out.

An UV CLARIFIER will have no impact whatsoever on algae stuck to pond sides, waterfalls or string algae floating on the water surface.

To control this kind of algae a bacterial product such as Viresco which is long lasting and is proven to work... many tests by independent experts have proven the efficacy of Viresco.

Regards

Tony Roocroft