Hidden Phosphates

[RareEarthCorals]

I have been trying to determine the causes for algae and bacterial outbreaks that we all experience from time to time. If this post does anything at least may it help others in diagnosing and process of elimination.

I started dosing in my ATO. I was using Red Sea nopox. The premise was based on feeding the right bacteria to aid in breaking down nitrates and phosphates. I thought it was my distilled water so I checked it. I had 0.00 readings. I have other chemical filters which kept the tank testing 0.02 which was acceptable but not breaking the algae and cyano hold. I removed and limited every source I was aware of and tried different methods.

Now we never think of testing our ATO reservoir. I tested my distilled water source and stopped dosing since I didnt think the nopox was helping. I have cycled out the water in the reservoir several times since.

So the distilled water I pour in the reservoir should be fine.... RIGHT!!!!

 

[RareEarthCorals]

Why is the distilled water in my ATO off the charts???

 

[Randy Holmes-Farley Verified Community Expert]

I do not know if that is a real result as opposed to test kit error. What source of distilled water? What is it stored in?

But even if it is a real, it is still a far smaller source of nitrate and phosphate relative to foods. Even if that is a real 0.25 ppm phosphate, you likely add 10-100 times as much in foods every day.

So while getting better water or a better container may be useful, it probably won't really make a big difference in the phosphate cycle in the aquarium.

 

[RareEarthCorals]

Those results are a second and third test from the reservoir. The water is store bought Nice brand distilled water kept in a 5 gallon container.

Point of this exercise, for the analytical mind, is process of elimination. Something we neglect to do when determining a possible source.

Point is that neither the distilled water, outside of the reservoir, nor aquarium has tested at this level. Yet the water sitting in the reservoir yielded these results, three times.

I don't feed the reservoir so I am unaware what has yielded the results. Left over issues from the nopox? Issues with plastics?

I disagree that changing the container, at a minimum clean it out throughly, would help as it would eliminate the only source that had the irregular test.

 

[chimmike]

I suggest in trying to eliminate a soruce, start with a source you know will have NO impact, i.e. pure RO/DI water. Eliminate all the controllable variables.

I agree that foods add far more, but if your filtration system isn't up to par to handle your feeding, cut back on the feeding amount or increase the capacity of the filtration system.

 

[Randy Holmes-Farley Verified Community Expert]

I disagree that changing the container, at a minimum clean it out throughly, would help as it would eliminate the only source that had the irregular test.

I'm not sure I understand exactly what you mean. I suggested that changing it might be useful, and it might be, but it is not the major contributor to phosphate in your aquarium (unless you do not feed).

If the container is made from recycled plastics, it could easily have some phosphate in the plastic that might leach out.

The reason we generally "neglect" these issues is that many people have measured them (getting real or erroneous values for phosphate, usually 0.05 ppm or less) in their own situations, but nearly always the contribution to phosphate levels in aquaria are not very important relative to other sources.

 

[Randy Holmes-Farley Verified Community Expert]

Perhaps this will help put these readings in perspective:

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.