BonniesPlants.com

The best and most efficient way to clear green water is to use a UV. Do you have a UV installed in your pond? A UV will clear up green water in 3-5 days if properly sized.
Steve

pond block turns your water blue or black like a mirror it is supposed to block the UV rays of the sun..... it helps very little. it does kill the alge some but with the die off you will be able to bloom more alge then you need to change the water and now your into more chemicals,. so now your water will be blue/green instead. your best bet is to get a UV sterilizer bonnie may have them if not look at several web site that carry them. the bulb is the most exspeive part after you own the system. it really needs to be replace most often times yearly i got 2 yrs out of mine and my pond sits in direct sun all day from spring to winter. very soon all the pond stores will be having the clearance sales and thats when you could buy one. or you could cover your pond with more plants. green doesn't hurt your fish just your pride of not being able to see your fish.

There are 2 things to clear green water.

UV
Plants hyacinths and hornwort love green water. With hyacinths being the my personal choice if you live in a state where they are legal AND if you have small enough fish that will not eat the roots off of them

Getting more surface coverage will cut back on the sun light. Plants will use up the nutrients that are producing the green water.

Bonnie

sheryle I was wondering if you got the 2 "PM" messages that I sent you.. if you don't know where it is ......its is by the user control panel under the board index . when you post a message and stuff............ let me know if you did or didn't and I will resend them...

yes the fish do love that green water and we don't but we can get it dealt with . my baby guppies love it as the can munch all day long if I'm not around to feed them for a couple of hours as they get fed up to 6 times a day to make them grow big so I can show them.

We intentionally raise all our fry in green water as they grow much faster. But in my personal pond, I would have a cow, so to speak, if my water was green.

Flocculent will clean up green water. It is for sale on my supplies page. That is what I use to clear green water when we harvest baby koi.

Do you know what your kh is? Do you test your water?


Bonnie

If you decide to purchase a UV light, make sure you check out the manufactures specs and pick one to match your flow rate. UV lights can function as either a sterilizer or a clarifier. As a sterilizer your water will become clear. As a clarifier you still may have a slight green tint to the water, but adding plants like water lettuce or hycinthia will help clear this (having a 50% or greater coverage).

The slower the flow rate, the more UV exposure time increases and your UV will function more as a sterilizer. The faster the flow rate, the less exposure time, and the more the UV functions exclusively as a clarifier. The water will take longer to clear at slower flow rates, and in some conditions (direct sunlight, overstocked pond, etc.) never achieve the same level of clarity as it would at higher flow rates.

You can control the flow rates of the UV with the use of a ball valve. The optimum flow rate is to turn over your pond once an hour or at a minumum once every other hour. Installing a ball valve allows you to experiment with the flow rate to see what best works.

As far as testing your ponds KH there is no "correct" answer. KH is a measure of the carbonate and biocarbonate ion concentrations dissolved in water. It provides the necessary buffer in order to maintain a steady pH. There is no magic number. Maintaining a high KH helps maintain a stable pH, preventing the possibility of a pH crash. Green water or algae growth can destabilze the pH of the water by producing CO2 at night to give low pH at sunrise, consume CO2 in the day to give relatively high pH at sunset. Higher alkalinity helps stabilizes this pH cycle. Adding baking soda is one way to increase your buffer. I also find using Koi Clay increases my KH. At a minimum you don't really want to go below 80 ppm. I try to stay above 125 ppm.

Steve