Nutrient export from refugium

[jocomp]

I'm sure others have encountered this (problem), so I was wondering how they resolved it? I am running a refugium that works well for keeping down nitrates and phosphates. I am constantly testing 0 and on both using hanna checker and Salifert. I've tried adjusting the light schedule. If the refugium light is only on a couple hours I start to notice algae growing on the display thank's glass, but still tests at 0. If I reduce the time to 1 hour a day, I finally get a low reading of nitrate of 1-2 (phosphates 0). But then I notice a significant growth of algae. I feel like I have plenty of nutrients in the tank even when its reading zero. There has to be both nitrates and phosphates if there is any algae growth... right? My sps are keeping their color as long as I don't run the lights all night. I guess my question is, how do I get an accurate reading while running a refugium?

 

[MarAquatic]

Good question but in guessing the reading you take is the factual reading of water currently in tank despite nutrient uptake.

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[jocomp]

I also wondered the accuracy so I have taken samples to 2 different lfs. They both had the same readings of 0.

 

[jocomp]

If I get my numbers up to 4 nitrate and .01 phosphate, I get too much algae growth.

 

[phc567]

Algae is algae. It will grow wherever there is more light source. So if you keep your display light on 10 hours and your fuge light on 3 hours. Guess where it’s gonna grow. So when you test these are hobby test kits. They are meh at best. So even tho it says zero but you see algae in your display. Well you got some phosphate and nitrate. It’s just the algae are using it up too.

 

[foreverreef]

I run my fuge and display lights opposite of one another when the tank lights are on thebfuge lights are off. When the tank goes dark for the night the fuge lights come on. This has worked for me for a long time. And I totally agree. Hobby test kits say 0 but in reality flat zero is tough to get.

 

[lapin]

Algae will grow on glass. I dont think it can be stopped in a reef tank. Magnet cleaners are a good thing for this.

 

[Scrubber_steve]

I'm sure others have encountered this (problem), so I was wondering how they resolved it? I am running a refugium that works well for keeping down nitrates and phosphates. I am constantly testing 0 and on both using hanna checker and Salifert. I've tried adjusting the light schedule. If the refugium light is only on a couple hours I start to notice algae growing on the display thank's glass, but still tests at 0. If I reduce the time to 1 hour a day, I finally get a low reading of nitrate of 1-2 (phosphates 0). But then I notice a significant growth of algae. I feel like I have plenty of nutrients in the tank even when its reading zero. There has to be both nitrates and phosphates if there is any algae growth... right? My sps are keeping their color as long as I don't run the lights all night. I guess my question is, how do I get an accurate reading while running a refugium?

If your corals are doing well, & color is good, I wouldn't worry about chasing the po4 & no3 numbers. Remember that algae's preferred nitrogen source is NH3/4, & the main source of that is from the fishes gills. Once assimilated no3 is taken right out of the picture, unlike nitrification where no3 is the end product.

If you only get algae growing on the glass & not the rocks, again I wouldn't be worried.