- Joined
- Jan 23, 2024
- Messages
- 171
- Reaction score
- 55
i know this is old but i had dino 2 days ago. today i have none. i ran the UV one night at 600gph on my 70 gallon aquarium, and the next night ran it at 380 gph. both fast turnover at 8x turnover and 5x turnover. and they are all gone. I had osteo dinos.In no expert at UV, but I'm a nerd and read a lot on the subject up to this point. There is an ideal flow rate to be calculated when trying to kill marine protests such as ich. Dinos are not as critical for flow rate because they are so small and easily irradiated by the UV.
Ideal placement is in the tank with an inlet and outlet both in the display itself and not plumbed in the sump or off a manifold. I found if marginally effective for ich until I removed it from my manifold and hooked it straight into my display.
Sizing of the UV is most important, you'll need much bigger than you thought originally, trust me. I had a 55-watt for my 215 gallon and after calculations, realized I need something in the 110 watt range with a flow of 300 gph to be effective.
Here's what I wrote for another reefer on reef2reef when he had questions on his unit:
You have a 150-watt HO Emperor you plan to use on a 300-gallon total water volume tank. Emperor suggests for killing marine protists (ich), you would need an exposure of 180,000 µWsec/cm2 running at 840 GPH to do that.
According to research by the University of Florida:
https://edis.ifas.ufl.edu/fa164
"Use of ultraviolet (UV) sterilization to kill theronts has been suggested, based on research involving Ichthyophthirius multifiliis (freshwater "ich"). The recommended UV dose for Ichthyophthirius theronts is 100,000 µWsec/cm2 (Hoffman 1974). However, UV doses required for Cryptocaryon irritans are anecdotal or extrapolated, and range from 280,000 µWsec/cm2 (industry numbers) to 800,000 µWsec/cm2(Colorni and Burgess 1997)."
So the extrapolated saltwater ich exposure needed to kill it with UV is anywhere from 280,000 to 800,000 µWsec/cm2. I've run with 336,000 µWsec/cm2 because I pulled that from a chart I saw many years ago for an exposure level to kill marine ich.
So to adjust Emperor's GPH from the 840 GPH needed for 180,000 µWsec/cm2 exposure to almost double the exposure suggested at 336,000 µWsec/cm2:
336,000 µWsec/cm2 ÷ 180,000 µWsec/cm2 = 1.87
840 GPH ÷ 1.87 = ~450 GPH
Running your UV at 450 GPH will effectively kill marine ich protists going through your 150-watt UV unit. The problem is most recommend at least a 3x turnover per hour for UV to be effective. Basically, the 450 GPH will kill any ich that goes through your UV, but if you don't have it turn over the tank volume at least 3x/hour, you're not killing enough of them to make a true impact to the population. For 3x turnover of your 300-gallon system, you need at least 900 GPH. So effectively, believe it or not, your unit is actually half the size it needs to be for your system as you're only running 450 GPH through it.
Again, these aren't hard rules of thumb. The 3x turnover is not a hard rule, just a suggested rule. The 280,000 µWsec/cm2 - 800,000 µWsec/cm2 extrapolated marine ich exposure value is not a hard line either, especially since it's just extrapolated from a freshwater ich exposure dose.
I just wanted to do the calculation for you to let you know where you stand and to give you comparison to suggested industry rules-of-thumb. Your own application and your intended purpose will help you decide what you really need to do. Just trying to help out a fellow hobbyist.
