UV Sterilizer and Freshwater w/ EBJD
- Thread starter cjbarth
- Start date
TangoWRX;3615844; said:
Read manufacturer recommendations with a grain of salt... They can state "Max Flow Rate" leading you to believe it will be effective at that rate... but in reality that's just the max pressure the housing can handle before risking a leak...
Even the charts that say "kills parasites at XXX gph" I wouldn't trust. People will comparatively shop and will purchase the unit that is claimed to be the most effective... so manufacturers have a very big motive to rate their product as more effective than their competitors...
But the reality is... all units are limited by the same science...
One may believe that a fatter unit will be more effective, as it allows more water to be inside the unit being treated at a time... But that is not true...
The UV rays will only penetrate so deep into the water. Therefore making the housing fatter than ideal just allows particles / parasites to move farther from the bulb where the bulb has no effect and not be treated.
I even question the effects of the fins that Turbo Twist and other brands boast. It is true that the close to the bulb the particles are the more concentrated the UV rays will be, so moving them around helps... but the fins themselves also hold the potential of blocking UV rays from contacting particles.
I am frequently amazed at how often manufacturers will create design "flaws" on purpose just to give them some difference from their competitors to focus their hype on...
Froma scientific perspective... the "fins" Turbo Twist boast about make the unit slightly less effective than it would be without them... I hate saying this, as Turbo Twist UV lights are decent units, but it is the best example in UV lights I know of...
Can somebody explain to me why a higher flow rate is bad, other than the risk of a leak?
Less effective per unit water because the water spends less time under UV....yes.....but more water gets pumped through....shouldn't it even out in the end?
I have three UVs...one is in a sump hooked up to a powerhead per the manufacturer's instructions, one is an in-tank unit that came with its own powerhead, and one is inline with an XP1 (no risk or flow rate too high there
). They all seem to work well....
Less effective per unit water because the water spends less time under UV....yes.....but more water gets pumped through....shouldn't it even out in the end?
I have three UVs...one is in a sump hooked up to a powerhead per the manufacturer's instructions, one is an in-tank unit that came with its own powerhead, and one is inline with an XP1 (no risk or flow rate too high there
). They all seem to work well....
If the UV housing holds 1 gallon of water… and you push 60 gallons per hour through the unit… each molecule of water spends an average of 1 second exposed to the UV rays…
Pushing it through at 300 gph… each molecule spends and average of 0.2 seconds exposed to the UV rays…
If 0.8 seconds of exposure would kill a parasite then the first situation would kill parasites, the second situation will not…
If 0.8 seconds of exposure is required to kill a parasite, it cannot be assumed that 4 passes at 0.2 seconds will kill the parasite…
*Please note I am not suggesting it takes 0.8 seconds of exposure to kill parasites… these numbers were substituted for example only…
Pushing it through at 300 gph… each molecule spends and average of 0.2 seconds exposed to the UV rays…
If 0.8 seconds of exposure would kill a parasite then the first situation would kill parasites, the second situation will not…
If 0.8 seconds of exposure is required to kill a parasite, it cannot be assumed that 4 passes at 0.2 seconds will kill the parasite…
*Please note I am not suggesting it takes 0.8 seconds of exposure to kill parasites… these numbers were substituted for example only…
nc_nutcase;3616745; said:
I totally agree, that is why my UV on my biggest tank is over rated to be sure. I would never run at the top limit as it would probably do very little, eg only effect algae and not pathogens.
The brand I use keep things simple and doesn't have any of these fins, but has a quartz tube over the top keeping a think layer of water passing through. As you say the UV doesn't penetrate far into the water..
Also yeah flow rates are important for exposure time on the water.
I thought UV induces DNA damage, which activates the checkpoint pathway during cell division and could lead to apoptosis.....wouldn't take too much time as long as a photon does its thing.....but if the optimal flow rate is determined empirically, there must be a good reason....and what you proposed does make sense...
nc_nutcase;3616901; said:
nc_nutcase;3609838; said:
Hi,
I am thinking of buying 2 of these for my 55g and 30g goldfish planted tanks. I have some green algae on my gravel, glass and so on...........not bad but I have them.
http://www.petsmart.com/product/index.jsp?productId=2750628&clickid=cart#prodTab1
Will these work? I am confused how big or how much gph is need it for my 2 tanks. Can you please advice? Thank you.
