IM UV - difference in performance between gravity fed and pump fed?

[Bohemian Waxwing]

Anyone have experience with the IM UV units?
They have a gravity fed and a pump fed for water supply. The pump fed is 1W more and double the price, but I’ve seen a couple people say they wish they had gone with the pump fed version.

https://www.jlaquatics.com/innovative-marine-auqashield-uv-sterilizer-9-watt.html
https://www.jlaquatics.com/innovative-marine-auqashield-universal-uv-sterilizer-10-watt.html

 

[PocketGoose]

I only have experience with the gravity fed model, so maybe this helps with your decision-making process.

I have the 9w gravity fed option in my 14 and I've enjoyed it so far. The flow seems to be slow enough for adequate contact time but the only issue I've run into is making sure that the water coming through the overflow goes into the bulb casing. I switched the sponge it comes with to filter floss and anytime it gets gunked up the water will then spill over the fixture and bypass the light tube. As long as you make sure water can freely move through whatever you decide to use for filter media, I think it's a great product and you can't beat the price. Water stays clear and I believe it aided me in a dino battle. If the units that includes the pumps perform like the gravity fed options, I'd say you can't go wrong with either.

Speaking of which, I think I'm due for a new bulb soon...

 

[Spare time]

What are you looking to achieve with it?

 

[Bohemian Waxwing]

What are you looking to achieve with it?

Battling dinos. I brought my nutrient level up and removed my macro algae, turned up flow. They dissapeared. However, now they are back with all those things in place. A lot of the threads I've found on here people have had luck with raising their temp + adding UV sterilizer.

 

[doubleshot00]

I have the second one as i have a media basket in my first chamber.

Battling dinos. I brought my nutrient level up and removed my macro algae, turned up flow. They dissapeared. However, now they are back with all those things in place. A lot of the threads I've found on here people have had luck with raising their temp + adding UV sterilizer.

What kind of dinos do you have?

 

[Bohemian Waxwing]

I have the second one as i have a media basket in my first chamber.

What kind of dinos do you have?

I am glad you asked - ended up reading through this document: https://www.reef2reef.com/threads/dinoflagellate-identification-guide.671466/.

No access to a microscope, but one thing I did noticed was that it was still on the sand this morning, so that makes me think it may not be migrating to the water column at night. My first bout with dinos/diatoms, they definitely migrated at night, and started up again once the light had been on for a while.

I'm going to do some small water changes this week and remove as much as I can mechanically before I look at equipment. I am not really in a rush, as long as it's a lower toxin type (surrounding my mushrooms).