OP
OP
Regarding UV sterilizers: I firmly believe in them, and understanding the difference between flow and turnover properly can maximize their potential.
People commonly describe UVs for binary uses:
To do both, you need to either:
1. Oversize equipment on Single Return:
Let's say you are working with a tank like a 90 Gallon, and you are using a very large 120W UV. The manufacturer specifies a max flow rate through the UV of 600GPH. At that flow rate, you would be hitting the kill rate for nasties AND you would be turning over the tank volume 6x, which is more than enough to slow down algae growth. Most 90 gallon setups don't have room for a big ole 120W UV sterilizer -- but the math does support the idea of suppressing both disease and algae at the same time.
2. On larger tanks, keep flow rates consistent for disease, and increase the number of UV channels/returns to be able to get overall tank turnover to the rate you need to combat algae growth.
For example, if I have one return line going through a UV that feeds my 550 gallon tank, and the manufacturer says 600GPH should flow through the same 120W UV, that flow rate of 600GPH will equate to a ~1x per hour system water volume turnover rate. Nasties will get zapped, but algae growth will outpace a 1x per hour turnover rate.
For me, I would like to have twice as much (2x) flow through the UV sterilizer to get enough algae zapped to slow its growth rate. But if I need 2x to help with algae, and I'm only allowed to have 1x before it stops killing nasties, the only way to solve for both is to add another channel.
Two different return channels, or 2*(1x turnover):
People commonly describe UVs for binary uses:
- Algae control - Regular flow rates will help with controlling algae, assuming that the turnover rate is high enough to keep pace with its growth
- Disease prevention/limitation - Low flow rates will help with disease by neutering free-floating nasties
To do both, you need to either:
1. Oversize equipment on Single Return:
Let's say you are working with a tank like a 90 Gallon, and you are using a very large 120W UV. The manufacturer specifies a max flow rate through the UV of 600GPH. At that flow rate, you would be hitting the kill rate for nasties AND you would be turning over the tank volume 6x, which is more than enough to slow down algae growth. Most 90 gallon setups don't have room for a big ole 120W UV sterilizer -- but the math does support the idea of suppressing both disease and algae at the same time.
2. On larger tanks, keep flow rates consistent for disease, and increase the number of UV channels/returns to be able to get overall tank turnover to the rate you need to combat algae growth.
For example, if I have one return line going through a UV that feeds my 550 gallon tank, and the manufacturer says 600GPH should flow through the same 120W UV, that flow rate of 600GPH will equate to a ~1x per hour system water volume turnover rate. Nasties will get zapped, but algae growth will outpace a 1x per hour turnover rate.
For me, I would like to have twice as much (2x) flow through the UV sterilizer to get enough algae zapped to slow its growth rate. But if I need 2x to help with algae, and I'm only allowed to have 1x before it stops killing nasties, the only way to solve for both is to add another channel.
Two different return channels, or 2*(1x turnover):
- Return 1 = 600GPH through UV (kill nasties)
- Return 2 = 600GPH or more (Increase overall system turnover to combat algae)
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