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UV Lights Wattage

 




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ykyap
Novice

Nov 14, 2009, 5:12 PM

Post #1 of 18 (9184 views)
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UV Lights Wattage Can't Post

Hi Guys,

Anybody knows how to do a proper wattage selection for UV lights to control algae to have a clear pond?
I read somewhere that it is related to our pond flow rate but I could not remember where I read it.

Thanks.

Regards.


raistlin
User

Nov 15, 2009, 10:27 AM

Post #2 of 18 (9141 views)
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Re: [ykyap] UV Lights Wattage [In reply to] Can't Post

Hi YK,

Based on what I've read before, there is a rule of thumb that says something like "1 watt per ton of water". I had a small 9watt overhead UV previously running on one of those tiny pumps and it was working fine on my 7ton pond (+filter). I believe 9 watt is probably one of the smallest size you can go. The pump broke down some time ago and the nice guys at Max came over to help me install a 18watt (I think) submerged UV. Whilst here they actually advised me to try switching the UV off and running it again if needed. So after running the 18watt for 2 days to make sure the UV was ok I decided to switch it off to see what happens.

It's been almost 2weeks and my water clarity is still good, minus the fact that I have issues with floating sediment I attribute to my badly located fountain pump. I noticed that for a few days after I switched off the UV, the water looked slightly 'milky' which I heard meant there was a bacteria bloom. Fortunately, my koi looks ok still and no problems occurred. Now it's actually improved and the water looks quite clear. I'm gonna keep trying to keep the UV off until I notice green water and keep my fingers crossed. Here is a pic of my pond recently. Sorry for the bad quality, I'm not a good photographer. The water in reality doesn't look so 'whitish' which I think is because of photo over-exposure.




Smile I'm deviating a little but what I'm trying to say is what are you thinking of achieving?

If the issue is green water, maybe the real solution is to look at your nitrates? If you deprive the free-floating algae of food (nitrates), then naturally there wouldn't be an issue. There are many other solutions to address nitrate levels but I guess the easiest is simply more frequent water changes. One thing to note is that it is almost impossible to avoid algae in an outdoor pond. It just a matter of whether it's free-floating algae or wall-algae. I believe in a new pond environment, free floating algae is usually the first to occur. But once the wall algae takes hold, it becomes dominant.

However, if your objective is for 'sanitisation' ie. bacteria level control then you probably can't avoid UV. In fact you probably need a high wattage UV for that purpose. The alternative may be an ozone generator but I think that method has inherent risks. So, if you want the forum sifus (obviously not me) to provide proper advice, maybe you should provide the following:

1) Purpose. (Green water prevention VS Sanitisation)
2) Tonnage
3) A brief description of your pond + filter
4) A photo would be good
5) Type of UV planned. Submerged VS External. I believe a lot of the kichis in this forum are advocating submerged. If it's not submerged then you have to start thinking about flow rates.

Best Regards,
Raistlin



ykyap
Novice

Nov 15, 2009, 5:05 PM

Post #3 of 18 (9128 views)
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Re: [raistlin] UV Lights Wattage [In reply to] Can't Post

Hi Raistlin,

I always measure the nitrates and they are within the acceptable limit. Why I am facing the algae problem is due to the following:

a) My pond is located on the north which the pond has sunlight all day long.
b) My pond does not have a roof over it.

I guess using the UV to control the algae could be logical choice.

Regards.


PH8
Veteran


Nov 16, 2009, 3:12 AM

Post #4 of 18 (9104 views)
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Re: [ykyap] UV Lights Wattage [In reply to] Can't Post

Good morning Brother Yap,Smile

Submerged UV lights are effective in dealing with free floating unicellular algae, but not with wall algae. It depends on whether you mind wall algae. These also have the potential to develop into string algae during algae blooms.

Other than free floating algae, it is also possible that your water clarity is affected by fines. From my experience with fines, these can be reduced/eliminated by -

1. Having a rotating drum filter or a dedicated settlement chamber (vortex or otherwise).

2. If not, then remove any airstones from your filter as the bubbling effect interferes with fines settlement in your filter chambers. Make sure the TDO level in your pond water is already high enough though, for the good bacteria to thrive.

3. Make sure your mats are packed wall to wall within your filter chambers, as any spaces would allow the dirty water to pass through the filter without being at least mechanically filtered. Water flow tends to find the easiest route.

Hope this helps.


Cheers,
Paul


raistlin
User

Nov 16, 2009, 7:02 AM

Post #5 of 18 (9057 views)
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Re: [ykyap] UV Lights Wattage [In reply to] Can't Post

Hi YK,

Not saying your nitrates are not acceptable. Smile Just saying if you want to solve algae issues, simply slapping a UV onto your setup doesn't really solve it. The UV does kill off the free-floating algae, but as long as conditions are good for algae, carpet or string algae will simply take over. That's my personal experience. Algae needs food (nitrates/potassium), CO2 and sunlight for growth. So if you control/deprive either one of the factors, you control algae growth.

Since UV is your choice of weapon, you can consider installing a submerged UV. I got mine from Max Koi Farm and I think 18watt is the lowest which should cover you for ponds up to 10 tons. However, you MUST consult the professionals for proper advice. Obviously the higher the wattage, the quicker the results but I guess installation and running costs should be considered. Alternatively there are overhead UV setups, but my personal experience with them isn't good.

Btw, you can also look at biological algae control. I've used a product called Interpet Blanket Weed Buster back when I had a string algae bloom (with my UV light running Sly). I was quite amazed by the effects. I combined it with physical removal of the string algae (scrubbing), but I noticed that the carpet algae was actually dying off after I used the product. It claims to use bacteria action to combat all forms of algae and so is safe for koi. In fact, I noticed after using it my koi had better appetite. Psychological? Maybe. Wink

Another method I've heard of is using ultrasonic waves to disrupt algae activity. But personally, I don't like the idea because I don't really think its good for our koi.

Best of luck in clearing your green water,
Raistlin


ykyap
Novice

Nov 17, 2009, 2:42 AM

Post #6 of 18 (9034 views)
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Re: [raistlin] UV Lights Wattage [In reply to] Can't Post

Morning Brother Raistlin and Brother Paul,

Appreciate that both of you took the time and effort to write such a detail explanation on ways to have a clear pond.

I used to have string algae but managed to control them when I bought a Oase Aqua Skim. This things works by sucking all the floating particles (including leaves) and at the same time will aerate the sucked water. If there is protein, you could see the protein bubbles bubbling in the basket.

I have also scoop up my pond water using fine net and you can actually see those caught in the net are actually algae. Brother Paul actually got what I mean clear pond water because I could see a lot of fines floating in my pond. I am trying to eradicate them.

Taking both of your advices, I have installed 2 nos. of 28watt submerged UV lights and will update both of you the results.
By the way, my pond size is only 9 tons.

Thanks again both for your replies.

Regards


PH8
Veteran


Nov 17, 2009, 2:59 AM

Post #7 of 18 (9028 views)
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Re: [ykyap] UV Lights Wattage [In reply to] Can't Post

Good morning Brother Yap,Smile

Fines in the water are not necessarily algae, though some of it may be. If you're using Japanese mats in your filter, pack them more densely, wall to wall. And make sure their tops stick out slightly from the water surface. I believe doing this, plus installing one submerged UV light, will reduce your fines problem significantly.

Not sure how your Oasis surface skimmer can deal with string algae.... CrazyCrazyCrazyAlgae blooms tend to be seasonal.


Cheers,
Paul


kelvinbay
User

Nov 17, 2009, 5:30 AM

Post #8 of 18 (8994 views)
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Re: [ykyap] UV Lights Wattage [In reply to] Can't Post

Hi bro Yap,

how long have you been using the Oase Aqua Skim and where did you get it from ? Saw a video of its usage sometime back but hasn't got a chance to hear from someone who has used it. Appreciate if you can share your experience.


Regards,
Kelvin


ykyap
Novice

Nov 17, 2009, 7:06 AM

Post #9 of 18 (8981 views)
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Re: [kelvinbay] UV Lights Wattage [In reply to] Can't Post

Hi Kelvin,

The Oase Aqua Skim is very good and the product can be deceiving because it is a very simple device a cyclindrical tower with a strainer on top and expensive because it cost about RM300++. This device must be attached to submersible pump with a capacity of 1600gph (minimum) to 4200gph (maximum) for the device to work. The pumps will be placed below the tower cyclinder and draws water from below to create suction on the top that draws all the floating materials on your pond surface. Besides this, somehow vortex is create in the strainer and thus will aerate the water that will cause foams to be created if your surface water is rich with protein.

Somehow, I took advantage of the pump outlet where I channeled it to a DIY bakki shower due to the high output of the pump. You can actually channel it to your existing filter but I found it caused to much disturbance to the filter brush or your first chamber. I have been using it since this year Hari Raya.

From this device I got few things:

1) Increased TDO from Bakki Shower
2) Nitrates and ammonia controlled
3) No floating debris
4) No oily surface
5) No floating algae
6) One happy customer.

Only Atari sells them at their outlet in Taman Desa and Tropicana.

Attached is a link to this product. Oase has a smaller floating type which plug and play type but accoding to Atari it is not effective besides selling at RM800++. IT is called Swinskim and can be seen in this website.

http://www.oase.ca/English/aquaskim.htm

Hope this helps.

Regards


PH8
Veteran


Nov 17, 2009, 8:43 AM

Post #10 of 18 (8970 views)
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Re: [ykyap] UV Lights Wattage [In reply to] Can't Post

Hi Brother Yap,

I don't think it's the Oase skimmer that does anything to your nitrates and ammonia. It's the bakki shower which is helping. It helps degas ammonia, and in so doing, the level of nitrites and nitrates (both of which are byproducts of the nitrification process) comes down also. This might help deprive the algae of food to bloom.

Surface skimmers are a must for every pond. SmileSmile In your case, your skimmer is probably particularly powerful since there is a dedicated pump just for it. For most of us, our surface skimmers don't have dedicated pumps and are just gravity fed.


Cheers,
Paul


ykyap
Novice

Nov 17, 2009, 9:15 AM

Post #11 of 18 (8948 views)
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Re: [PH8] UV Lights Wattage [In reply to] Can't Post

Hi paul,

In my initial installation of the skimmer, it did come accross my mind to divert the pump output to a Bakki Shower. The pump output is positoned below the water level. Strangely, it does resolve the foam on the surface maybe by 70%. I could not offer an explanation to this and somehow it works. Probably why the product is expensive!

Regards.


raistlin
User

Nov 17, 2009, 11:41 AM

Post #12 of 18 (8928 views)
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Re: [ykyap] UV Lights Wattage [In reply to] Can't Post

Hi Bro YK,

I also need to learn how to have a clear pond, there's also alot of floating sediment in mine. Maybe after you've solved your problem you can share it with me. Smile I merely shared what I've experienced and read about algae.

Your UV is definitely very powerful! Wink Maybe even high enough to control the coliform level. heheh. Just jking I don't know...

I agree with Bro Paul about the bakki helping out with Nitrates and Ammonia. The bubbles u see just means high surface DOC if I'm not wrong. I sometimes get that in my Surface Skimmer after feeding Saki Hikari, coz it creates an oil slick on the water surface.

Best Regards,
Raistlin


lamig747
User


Nov 17, 2009, 1:07 PM

Post #13 of 18 (8916 views)
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Re: [raistlin] UV Lights Wattage [In reply to] Can't Post

Hmmm...somehow I have a feeling someone made money from you. 56 watts UV for a 9 ton pond??? As raistlin said, it could be good to kill bacterias - good AND bad. I have a 6 ton pond installed w a 9watt UV and it worked very well until I guess the filters matured and I turn them on when my wife complains she sees green (about 10 days after) and my pond receives sunlight from 8 am till 3pm due to its different direction this season (it was received only 2 hours back in March). Sorry if I im a little too direct/frank.

My bulb actually busted out last week and while theyre available locally (no name brands) i thought of googling them and ordered from ebay for 3 pcs at the price of 1 fr the US. Still have to receive them though.

Rgds


davidw
Novice

Jan 14, 2010, 10:04 AM

Post #14 of 18 (8391 views)
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Re: [raistlin] UV Lights Wattage [In reply to] Can't Post

Hi,

Can I conclude that the advice on submerged UV lights is to switch on only when necessary albeit presence of green water? My pond has just been cleared of green water after installing submerged UV in the pump chamber and I intend to switch it off.... many thanks in advance


cookcpu
User

Jan 14, 2010, 10:37 AM

Post #15 of 18 (8380 views)
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Re: [davidw] UV Lights Wattage [In reply to] Can't Post

Yes you can switch it off if your pond water is clear.

I normally left the UV light on unless I have put medication in my pond or I want to test how mature my filter is currently.


raistlin
User

Jan 14, 2010, 4:13 PM

Post #16 of 18 (8348 views)
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Re: [davidw] UV Lights Wattage [In reply to] Can't Post

Hi Davidw,

Not sure whether I understand your question, but anyway my personal opinion is:

It depends on your objective for the UV. If you're only using it for clearing green water, why keep it on if your water is clear? Unless you know once you switch if off, the green water will come back. (Due high nitrates etc.) Then maybe you need to address the issue of why the free-floating algae is growing so fast? Start doing more water change? Are you over-stocking?

Some people use their UVs to sterilise the water. ie. control bacteria level (you need very high wattage then). If your UV is used this way then you should not switch it off.

Btw, still haven't switched my UV back on after 2 months and still clear. Koi still feeding very well so all seems fine.

Best of luck!


davidw
Novice

Jan 15, 2010, 10:09 AM

Post #17 of 18 (8316 views)
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Re: [raistlin] UV Lights Wattage [In reply to] Can't Post

hi cookcpu,
thanks for the confirmation....

hi raistlin,
thanks for the advice, reason for question is juz like to know the general practice for pond hobbyist on UVC....usually i keep my UVC on 24/7 for prevention of greenwater and sterilization especially for my aquariums (enclosed type), and this is the first time I'm using a submerged UVC and for my first pond too Laugh, so not too sure whether it is effective for zapping bugs (btw its 15w or 12w? I think, need to re-check), so since greenwater is gone might as well switch it off, not that it will save on electricity but perhaps to minimise untoward events, some itchyhand neighbour kids or friends of my kids might just open the chamber cover to take a peek when I'm not around..... btw my bio load is pretty low, only 3 kois and some other fishes for a 4-toner but I do get massive sunlight, currently planning some kinda shade.... cheerz


(This post was edited by davidw on Jan 15, 2010, 10:11 AM)


jcwc
Novice

Jan 25, 2010, 3:21 PM

Post #18 of 18 (8190 views)
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Re: [davidw] UV Lights Wattage [In reply to] Can't Post

Hi, good discussion on UV lights. I have a 20W UV light which I leave on 24/7. I didn't know you can turn it off once the water clears (so thanks for that tip).

I wanna ask where is the recommended place to put this UV light? I have a 6 chamber gravity fed filter. Presently my UV light is in chamber no. 2.

 
 
 



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