Polished aluminum shavings in tank?

[Reefmiester]

Randy,

I asked this question in Rons forum and he sent me over here.

I have a new tank running and was installing polished aluminum sheets inside the canopy. I covered the top of the tank with plastic to help prevent anything from getting in, however a small shaving of aluminum did fall into the tank when removing the plastic. It was about a 1/4" curly Q made from drilling a hole. The problem is I have over 400lbs of LR in this tank and it fell right between the base rocks.

Should I worry about this peice and tear the tank down to try and find it? The other issue is that I have 4" of sand in there too. What are the potential risks in leaving it in there?

Thanks!

RB

[Randy Holmes-Farley]

I expect that it will slowly dissolve and go unnoticed. Too much aluminum released to the water can cause problems, as I show in this article, but I don't think that is enough to worry about:

Aluminum and aluminum-based phosphate binders
http://www.advancedaquarist.com/issues/july2003/chem.htm

In the tests shown below, I found that 0.05 ppm did nothing that I could detect, but 0.5 ppm did cause difficulties for some corals:

The second aluminum addition boosted the aluminum concentration by 0.045 ppm by adding 1.35 mL of an aluminum chloride solution to the water (total additions = 0.05 ppm aluminum). A pH electrode was in the water at the time and recorded a pH drop of from 8.35 to 8.33-8.34 pH. There was no apparent change in any corals in 24 hours.

The third and last aluminum addition boosted the aluminum concentration by 0.45 ppm by adding 1.35 mL of an aluminum chloride solution to the water (total additions = 0.5 ppm aluminum). A pH electrode was in the water at the time and recorded a pH drop of from 8.35 to 8.25 pH. There was no apparent change in any corals in 1 hour. By the 5-hour mark, the leather coral had closed (pH = 8.30), and then it began cycling between open and closed every hour or two, continuing into the next day. Figure 4 shows the closed form.


Thirty six hours after the last aluminum addition, the leather was still cycling between open and closed. This behavior had not been exhibited by this coral prior to aluminum additions. While I cannot be certain it was a result of the treatment, it seems likely."

That piece of aluminum that you had might have weighed 0.2 grams (a guess), so if it all dissolved immediately (it won't), it would boost the aluminum concentration by about 0.2 grams/240 gallons? = 0.22 ppm.

So since it will dissolve slowly, and aluminum seems to disappear from aquaria over time, I expect it will be fine. :)

[Reefmiester]

Thanks Randy

[Randy Holmes-Farley]

You're welcome.

Happy Reefing. :)