Comments on Aquarium and pond UV Sterilizer: UV Sterilizers Truths

The information I have shows that the Eheim 2322 h...

2008-09-29T07:01:00.000-07:00

The information I have shows that the Eheim 2322 has a flow rate of 500 l/ph (132 gph) which is proper flow rate for a 9 watt Turbo Twist using watts per gph as a guide.
This is not a 100 % accurate guide, however watts are a very accurate guide as to output of UVC radiation since we are dealing with apples to apples comparisons of the low pressure UV bulbs commonly used in UV Sterilizers employed by the aquarium industry.
Other factors includes the flow design such flow pattern and volume of water between the lamp or quartz sleeve and the UV Sterilizer wall. Water Temperature is also a factor in low pressure UV Bulbs.
The Turbo Twist is an average UV Sterilizer in my experience based on factors other than wattage output (there are better and much worse units).

Back your question, your peak flow rate (at 0 head pressure, so likely your flow rate is lower) places your unit in an effective zone for UVC radiation. 20 -30 gph (75- 115 l/ph) per watt is generally effective for most UV applications, although for parasites kills, you will need to be under 10 gph (38 l/ph) per watt, which is usually not possible in most applications. At 9 watts that equals 675 l/ph for your Turbo Twist.
You can slow down water if you choose by placing your Eheim lower from your tank surface thus adding to head pressure.

For further information, please see these articles:
UV Lamps (Bulbs) and how they work
UV Sterilization

I have just bought a turbo twist 9w.The instructio...

2008-09-29T04:26:00.000-07:00

I have just bought a turbo twist 9w.
The instruction pdf comes with an incomprehensible chart which uses flow rate on one axis and microwatts per cm per second as a measure on the other axis (i'm not sure if thats right but its a radiation measure of some sort). My pump (eheim 2322) flow is 350litres per hour but i can adjust flow a little prob 10%, i think this is about 90 gallons per hour. The tank is small at around 50lires. Why do the ratings say this uv unit is for this volume tank when surely the flow rate is the measure of performance???
Now you say uv wattage of the bulb is an ok measure to use. Are you sure the wattage relates closely to the radiation output? I hope so because watts of bulb is easier for me to understand!
Anyway i want to kill as much bugs as possible. I like the size and the price of replacement bulbs for the turbo twist, but now i'm wondering if i should upgrade from 9 watt to a 18 watt unit. Can anyone advise??

I do not have any current data as to “UV lamp effi...

2007-12-23T15:12:00.000-08:00

I do not have any current data as to “UV lamp efficiency at different operating temperatures as would be the case if a quartz tube was used or whether there is direct water impact with the UV lamp”
I also used to have some of this information from Phillips as well, but did not retain this.
What I can say is that from my own experiments and tests that I not observed a more than 5 degree F difference between these tow types of units and in fact some quartz sleeve units were actually worse due to poor housing design. I have a particular unit that I have replaced several Tetra Quartz Sleeve models with in ponds and have had measurable results observed by myself and clients.
I address some of this question in this article (which has just been updated as of this reply): Ultra Violet Sterilization

Someday I will make a blog post on this subject after more facts and tests are gathered.

Do you have information on UV lamp efficiency at d...

2007-12-23T02:50:00.000-08:00

Do you have information on UV lamp efficiency at different operating temperatures as would be the case if a quartz tube was used or whether there is direct water impact with the UV lamp. I once had Phillips info but have lost it. Thank you
Tony
Water in the Home and Garden