How to calculate UV GPH for ick management

Schulks · Feb 1, 2023

Hello, I am trying to figure out how to calculate the GPH I'd need for this unit - https://www.aquacave.com/aqua-ultraviolet-15-watt-advantage-2000-in-line-uv-sterilizer.html - to control ick and other diseases.

I think it is around 100 but I can't figure out how to properly calculate it.

Thanks!

I found a post the other day that gave a lot of information and some rough equations for calculations but I can't find that thread in my history. If anyone knows what I am talking about lmk!

(I should have put a question mark in the title..)

Big G · Feb 1, 2023

aqua uv 15w-gph needed for ICH management

I just got the 15w classic UV sterilizer-aqua ultraviolet. At what GPH pump should i run them for Ich management? It is intended for a 40g tank. thanks!

www.reef2reef.com

Schulks · Feb 1, 2023

Big G said:
aqua uv 15w-gph needed for ICH management

I just got the 15w classic UV sterilizer-aqua ultraviolet. At what GPH pump should i run them for Ich management? It is intended for a 40g tank. thanks!

www.reef2reef.com

Most the threads that talk about this are confused by the manufactures recommendations which seem to use freshwater ick to trick us into thinking it is better than it is. Maybe I should rephrase and repost this in the treatment section

Tamberav · Feb 2, 2023

There isn't really much research into the amount needed to sterilize SW ich. That is why there is confusion. The fact we call both FW Ich and SW Ich "Ich" doesn't help even though they are completely different parasites.

So I guess what number did you settle on in hopes of sterilizing ich? From there you could calculate it.

“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).”

FA164/FA164: Cryptocaryon irritans Infections (Marine White Spot Disease) in Fish

University of Florida, Institute of Food and Agricultural Sciences Extension outreach is a partnership between state, federal, and county governments to provide scientific knowledge and expertise to the public. The University of Florida (UF), together with Florida A&M University (FAMU)...

edis.ifas.ufl.edu

So if we go with aquaculture's use of marine ich at 280,000 divide by 90,000 (Aqua UV rating) = 3.1 - that is how much we need to slow it down by. Aqua UV recommends 233 gph for 90,000... so 233 divided by 3.1 = 75.16gph.

Turnover ideally should really be 2-3 times an hour of the tanks volume but we really can't do that with a 15 watt unless it is a nano. You can get 1 turnover an hour on a 75g which would be the minimum I would go otherwise get a larger UV.

If you go by BRS/Pentairs general recommended parasite control of 180,000 then you would divide by 2 which would give you 116.5gph. This is probably more feasable for hobbiests though perhaps less then ideal.

Like I said, not a ton of research or agreement on what is exactly needed.

Please be aware that head pressure and so on will effect flow through your UV and pumps rating are often not correct so don't go by whatever the pump is rated to push. Measure it.

Schulks · Feb 2, 2023

I don't believe the UV dose and GPH scale linearly. I think you get diminishing returns as you slow it down.
I asked Ultraviolet what is the slowest it can run before burning up and if that can achieve 290k UV.
Will report back soon.

I definitely understand how pumps aren't accurately rated! I have a couple pumps a 300 gph and 266 gph and the 266 is about twice as strong.. I had to switch my return pump around lol. I plan on using a bucket fill test to test the speed in the UV.

This is actually for a 25 gallon cube so the tank turnover might be solid enough.
However, since discovering how difficult it is to reach the 290k exposure I considered a cheaper UV just for algae/water clarity control. That would still be a lot of the cost of the Aqua Ultraviolet.

I'm likely going to just accept I can't reach 290k still get the 15w and get as much of the dose as I can. like you said it is unresearched anyway..
I will run the 15w as slow as possible(<100gph) most of the time and turn it up occasionally.

Tamberav · Feb 2, 2023

I think you will be fine doing that, the tank is small and actual water volume even smaller after rocks and such. I think I am used to people asking if they can put a green machine on their 75g or a 15w on their 180g.