UV heat generation?

[gbroadbridge]

@strich I want the UV to help with parasite control and be able to toggle it to help with algae. Water clarity is a very nice bonus too.

@gbroadbridge I am using pentairs manual. For the 18w at 37-60 GPH exposure would be 180,000 uw/cm2. Are you saying this is outdated information? Was there some recent studies done? Thanks

Pentairs manual lists up to 60 gallons and I'll be just over that. I figured it would at least help. I could change the bulb early and keep flow on the higher end of recommended.

Edit: oh you mean the pentair manual is based on freshwater ich duh.. so I need 280k uw/cm2 exposure?

The latest chart I have is attached below. It is a metric version of the Pentair commercial documentation but you can convert back simply enough. LPM / 3.79 = gallons per minute flow.

FWIW, I have worked professionally on the design of ornamental fish quarantine and treatment systems.

 

[Doctorgori]

yes, all my tanks went up about 2F with properly sized unit
yes some water clarity for algae &/ bacterial blooms but not to be confused with ozone which is more molecular than a bio zapper/sterilizer


just adding my sample…

 

[The_Paradox]

First, UV does not kill anything, it sterilises the organism so that the organism is incapable of reproducing.

While the mechanism of action (MOA) is inactivation for some microbes, it must certainly kills others through different means such as apoptosis. So…

I'm sorry, but this statement is plain wrong.

 

[gbroadbridge]

While the mechanism of action (MOA) is inactivation for some microbes, it must certainly kills others through different means such as apoptosis. So…

Which is exactly what I said.

The damaged cells are thus incapable of regeneration (aka sterilised).

 

[The_Paradox]

Which is exactly what I said.

The damaged cells are thus incapable of regeneration (aka sterilised).

Correct. Things that are dead cannot reproduce. You said UV does not kill cells.

 

[strich]

I'm sorry, but this statement is plain wrong.

First, UV does not kill anything, it sterilises the organism so that the organism is incapable of reproducing.

Second, most beneficial bacteria in a tank are on surfaces, there is virtually none in the water column.

The other poster has essentially addressed it, UV sterilizers absolutely destroy the DNA and therefore the cells of many organisms going through it. So yes it does destroy beneficial bacteria.

However I will concede your other point is accurate - most volume of beneficial bacteria is not free floating in the water column and therefore won't be as freely destroyed as negative viruses. I hadn't considered that.

 

[gbroadbridge]

Correct. Things that are dead cannot reproduce. You said UV does not kill cells.

It does not kill the cell, it damages the DNA contained within the living cell.
The cell survives, it simply cannot reproduce.

Eventually of course, this results in a no living organisms left provided that you are sterilising them before they get a chance to reproduce.

This is why it is essential that the UV dose is high enough and that the tank water volume is turned over at an appropriate speed.

Dosing charts for professional UV systems are published so that the radiation exposure is sufficient, and that the flow rate can turn over the aquarium volume fast enough for adequate sterilisation.

 

[strich]

Okay I understand your position now @gbroadbridge and you're right in what you say, thanks for the info.

 

[Schulks]

@gbroadbridge Thank you for sharing your wisdom here!

I found a new 25w pentair locally to me. I could I set this up with my 18w and be at 43w. I'd have to use a 1/2" connection between the two units as that is what I have glued in right now. Is that a bad idea? I gotta lowball him or else Id rather just buy this,

https://fishtanksdirect.com/emperor-aquatics-smart-40-watt-uv-sterilizer/ .

I'm not sure why it is still branded emperor aquatics since they were bought out 10 years ago now...

 

[The_Paradox]

It does not kill the cell, it damages the DNA contained within the living cell.
The cell survives, it simply cannot reproduce.

That is incorrect but ok.

 

[strich]

That is incorrect but ok.

You're both right - UV sterilization can damage only DNA and not outright kill the cell. It can also outright kill the cell. All depends on UV dose params.