UV or not to UV?

[GarryT]

Well I've got the dreaded green (actually brownish green) water. I've checked all levels and everything is AOK, PH around 6.5, 0 nitrates, etc. I thought it would clear on it's own but it appears not to be, at least not in the short pond season we have up here in Canada. The pond is about 400 gallons with a bio filter feeding a 20' stream with a 1000 gph pump. No algae on the rocks in the stream bed except at the edge of the water fall into the pond. As an experiment I purchased some of the miracle NU Foam that I hear so much praise about and folded a chunk into the outlet of the bio filter. And ....ewwwww, within an hour lots & lots of green brown crud. I doubled up on the Nu Foam and cranked the pump down a tad because the additional restriction of the NU Foam was causing the filter to backup & overflow. I cleaned the pads twice a day. Sort of a temporary experiment but after two days things were noticably better.

The only thing is now my babbling brook is down to a trickle & I have these pads sticking out of my bio filter so a more permanent solution is necessary. I'm as much as a back to nature guy as you can probably get ....hence the bio filter but would also like to see my fish now & then. So the decision is to turf the bio filter & get a combination UV/mechanical/bio filter or is just adding a UV filter going to do it? I need the voice(s) of experience. Will the bio filter alone catch enough of the dead algae that the UV is supposed to kill or is additional mechanical filtering going to be necessary? At the moment it looks like the suspended algae goes right on through it.  I definitely do not want to resort to chemical treatments for algae. The pond is very lightly stocked with 4 - 4" GF and has about 40% floating vegetation cover and is exposed to only 4 - 5 hours of direct sunlight per day.

....Garry

[Jonna]

the brownish part is dead algae so something may be working.  When I have murky water, usually just after I have been in there mucking around or after I dump in some koi clay, I put cotton batting in the waterfall and hose it clean as often as I have to until the water clears.  Sometimes I have to clean it many times in one day.  You know, koi clay would be a good thing for you.  It's organic, it is good for the fish, it collects all the dead and brown stuff and clots it up to either settle on the bottom or end up in your batting if you are too impatient to wait for it to settle.  That's me.  I can clear the 2000 gal pond in a day with cotton batting and the pump set to push everything through it.  I have caused the skippy to overflow when I had it inside the skippy, so now I just set it under the water fall on the rocks where the water can't back up and overflow.  Once it is clear, it seems to stay that way on its own unless I get back in and make a mess.

[miguynmkoi]

I've done the same as Jonna.  I also put an aquatic basket lined with polyester (someone says it can withstand more punishment by water hose) quilt padding which I remove and rinse when it looks pretty cruddy.  I only use this method when the brown dead stuff gets out of hand, around this time of the year for about a week, and when the dipsy  tip over my lilies (not that often but at least once a year) and create lots of soil particles stirred up in the water.  The out of filter box padding basket eliminates problems of blockage.  Worst that can happen is the padding falls back into the pond and I have to start all over 

UV is just more stuff.  Rather sit and enjoy feeding my rascals 

[Ky Kim]

I like doing things natural as well, BUT . 
How old is your pond? 
Is it pretty new? 
How many fish? 
Plants?

Reason I'm asking is wondering if its still just cycling. 

The brown stuff does sound like dead algae,  unless you get that out it will feed another algae bloom.  Quilt batting works wonders on algae, just be sure to get polyester kind, the cotton will fall apart. 

[Jonna]

You guys are both right, my batting is polyester too.  I just was looking at the bag.  It's the quilt stuff from WalMart.

[GarryT]

The pond could be cycling, it's only 2 1/2 months old but with our short pond season here I guess I'm a little impatient. At best I'm guessing that we only have 1 month left with the GF coming out in early October when water temps will be getting fairly low (around 60F now). By mid to late November I suspect that it will be well on it's way to being a very large ice cube. I've noticed that the lilies have stopped blooming in the past 2 weeks no doubt from the cooler water temps. Hopefully the algae is slowing down too. Other than that, the GF (4 of them each about 4" long) are growing like weeds so everything seems to be happy. Is it reasonable to have a pond cycle and stabilize in a period of 4 1/2 months which I'm guessing, would be a typical pond season up here? Or do we resort to other measures such as a UV filter to stabilize the water? I would be interested in hearing from other "cold" water enthusiasts.

I completed the pond under some fairly icky conditions, lots of rain, mud, etc. so I'm thinking that there may be a fair amount of construction gunk (which of course I can't see now) on the bottom. That in combination with the leaf bits and pieces that I've missed retreiving on the twice aday scooping session (don't you just love trees!). I've dredged the bottom with a fine net and picked up only a few peices of debris, most of it appears to be decomposed silt. Again, not being able to see the bottom is somewhat of a handicap.

So maybe I'll just tough it out to the end of the season and then give it a good cleaning in the spring. Kimberly, I love the idea of your indoor pond. I was considering buying an aquarium for over wintering the GF but I do have extra liner available from the pond that I could make into an indoor pond similar to yours. Bigger, cheaper and could possibly save some of my floaters. I wonder how the hardy lilies would fare in there if kept in realtively low (compared to outdoors) lighting conditions? Or is it best just to trim them down and put them in a dark, cool place for winter?

So many questions .... Garry

[Rocmon]

You added filter pads to your biofilter outflow and are bummed they are collecting so much crud they are clogging? But the water is getting cleaner? Your on the right track there.

The mechanical filter which comes before the biofilter is where the physical debris should be collected. The biofilter is for biobugs to convert nitrates, nitrites, etc. to plant useful materials. It should not be a mechanical filter. Mine is to some degree because I also don't have adequate mechanical filtration. A bottom drain would also help to remove the construction crud.

Yes ponds take time to cycle. My pond when first starting up was getting quite green, just as the visibility seemed to be getting to be really bad the biofilter kicked in and in a few days the water was clear. Water changes can help to remove excess nutrients as well, but you need to give your biofilter some time to cycle. You also don't clean the filter media in it with hose water—just a pond water rinse.  The biobugs don't work much below 50–55 degrees. They say you can buy some expensive biobugs and your pond should take about six weeks to cycle, without them it could take as long as six weeks to cycle.

Green algae grows from an excess of nutrients. A UV filter kills green algae. The dead algae then releases the nutrients again for more... green algae. What you want to do is have adequate filtration to remove the crud and excess nutrients. Plants will help—Water hyacinth are great for this, I also have good luck with Watercress. You can't have to much filtration...

[milliemax]

   I'm pretty new at this, but between the filters and the UV my pond water cleared right up!
  This is the right time of year to purchase them on sale. I got my UV last year at about 1/2 price. I've heard of alot less.
  Nancy

[spanishleprachaun]

Just my 2 cents.  I live down here in hot and humid south texas.  With warm water,.. we all know the GREEN SOUP is quick on the scene when there is not proper bio to combat the nutrient levels in the water, and starve out the single cell algae.  I've had amazing success with always implementing plenty of water plants and bio-media in the filter area to stabilize the pond as fast as possible.  I can honestly say the only pond that went A LITTLE green on me was the pond I built inside of a swimming pool.  Over 6500gallons.  Within 2 weeks water was CLEAR !!! Lots of plants in the beginning and a 300gal skippy filter with 2 spools of bio ribbon.

Never have used a UV in any pond I've done.. and never will.  If there is no room to expand for more BIO MEDIA in a filter.. or if more water plants are out of the question... then I could see UV coming in.  But with the initial cost-- and then bulb replacement every year -- making sure you ARE RIGHT ON the flow rate from the pump.... eekkk... just not my thing.
good luck though !

[Bonnie]

BUT
A UV is great to use until your pond cycles.....

Yearly Bulb replacement isn't needed when you only use it when you first start up your pond.....  just my 2 cents!

[spanishleprachaun]

Excellent point Bonnie....!!!  I should have clarified that I'm use to folks down south here using them 24-7 all year long.

[GarryT]

I've been away from the forum for a while so it was interesting to see all that great feedback. The long & short of it was that I purchased an inexpensive Chinese knock off pressure / UV filter and connected it temporaily to the feed to the biofilter. A week and a half later crystal clear water. I regret that I waited so long. Next spring I'll find a permanent home for the pressure filter. After a month long battle with leaves (lots of trees in this neighbourhood and very windy days), the fish are now in the basement in their winter home. I left everything running in the pond because of all the birds that frequent the stream for a drink or bath until it freezes up (We have had a thin layer of ice overnight a few times now) then pull the pump.

Now 6 months of snow & ice ahead ......brrrrr!