Phosguard or GFO in top off water

Slevin007 · Nov 19, 2015

I was wondering if anyone has ever tried placing a bag of either or something else into their ATO storage container or their premixed salt water container just in case

I am just curious if anyone has thought of this or has tried this to ensure their water is clean. I use to RO/DI so I've never tried this but figured it might not be a bad idea. Any thoughts?

Reefing Madness · Nov 19, 2015

If your RO/DI tests out 0, and TDS is 0, theres really no need for anything.

Slevin007 · Nov 19, 2015

True. Still curious to see if anyone has done it or thinks it might be useful. Maybe as a precaution for an inaccurate TDS meter or something.

Doesn't seem like there would be any ill effects.

Randy Holmes-Farley · Nov 19, 2015

Not much benefit, IMO. The detriments are likely minor.

NanaReefer · Nov 20, 2015

Useless IMO plus a waste of money.

Slevin007 · Nov 20, 2015

looks like everyone's on the same page.

AZDesertRat · Nov 20, 2015

GFO and similar medias depend on multiple passes through the media to be effective thus the reactors which recirculates the water. If your RO/DI is efficient there is no need to do any further treatment, if not improve or upgrade the RO/DI system.

saltyfilmfolks · Nov 20, 2015

The phosphates stick to the the actual media. The media.GFO isn't adding something to the system. Like dissolving an aspirin
It need to touch the water Colum to pull out the Po.
Putting it in the top off is pulling the Po only from the water in the tipoff.

Randy Holmes-Farley · Nov 21, 2015

saltyfilmfolks said:
The phosphates stick to the the actual media. The media.GFO isn't adding something to the system. Like dissolving an aspirin
It need to touch the water Colum to pull out the Po.
Putting it in the top off is pulling the Po only from the water in the tipoff.

I expect that was the goal: making sure the top off water itself didn't have significant phosphate.

However, even if it does have a small amount, it is unimportant relative to foods.

I address that here:

http://www.advancedaquarist.com/2012/3/chemistry

from it:

Comparison of Food Sources of Phosphate to Other Sources
What about other sources of phosphate, like the "crappy" RO/DI water containing 0.05 ppm phosphate? A similar analysis will show it equally unimportant relative to foods.

Let's assume that the aquarist in question adds 1% of the total tank volume each day with RO/DI to replace evaporation. Simple math shows that the 0.05 ppm in the RO/DI becomes 0.0005 ppm added each day to the phosphate concentration in the aquarium. That dilution step is critical, taking a scary number like 0.05 ppm down to an almost meaningless 0.0005 ppm daily addition. Since that 0.0005 ppm is 40-600 times lower than the amount added each day in foods (Table 4), it does not seem worthy of the angst many aquarists put on such measurements. That said, tap water could have as much as 5 ppm phosphate, and that value could then become a dominating source of phosphate and would be quite problematic. Purifying tap water is important for this and many other reasons.