reincarnation rock process and phosphates

[Alesici]

This thread starts from this discussion:

 

https://www.nano-reef.com/forums/topic/380581-ammonia-levels-wont-go-down-during-cycling-with-dry-rocks/?page=2#comment-5490958

 

of which I report a short summary below.

 

Coming from a 5-years  fresh water hobby, my story with salt water tank starts when  I "intercepted" some rocks from a friend who was getting his tank off. So, I took the rocks which have been kept in that tank for fifteen years. Never I have seen his tank, but I strongly believe that his conducted  the tank in a very scruffy way.

 

To make those rock usable, I step-by-step followed  the rock reincarnation process instructions fromhttp://www.reefcentral.com/forums/showthread.php?t=1914426

Thus, the first days of february I set up  a five gallons nano reef using those reincarnated rocks plus new silica sand, a bag of which I already had for my fresh water tank.

 

The cycling process was kept under control and with light off all the time. As a source of organic matter I added flake fish food, a good pinch once a week. The process was very slow (as it's actually claimed in the instructions).  

 

After one month I checked for phosphates resulting very high being at  3 ppm!!

 

However, no algae appeared in the tank, just the water was a little cloudy due to the high level of ammonia, I guess.

 

Since I added good pinch of flakes  during the cycling process, I thought  this could be the cause for a such high value of PO4, as I read from section "Phosphate Sources in Reef Aquaria" in http://reefkeeping.com/issues/2006-09/rhf/index.php.

 

So I stopped to add  any organic matter to the tank, but just pure ammonia to feed bacteria.

To understand the real cause of such high phosphates and to check conjectures from the people in the forum, I also made the following  "not rigorous" experiment.

 

In a bowl I put just half inch of new silica sand and new salt water. I stirred the sand twice a  day. In the meanwhile I was keeping to do weekly water change in the tank.

 

After one  week I tested  for PO4 from the water in the bowl resulting 0 ppm. So, I could say that Phosphates did not come from the sand I used in the tank.

 

The same day phosphates test  of the water from the tank gave PO4 again at 3 ppm!

 
After the test I made another 40% WC  so that PO4  were put at  1ppm.

At that point I  conjectured   the origin of phosphates could be:

 

EITHER the flake fish food I put in the tank during the cycling;

 

OR the rocks although they  have been reincarnated.

 

To cross out some of the above options, I added a good pinch of flake food into the bowl while  I left the tank as it was with no addition during the next week: no any organic matter, no pure ammonia. Nothing. Or to be more precise, just RO water to supply the evaporation. (I also say that I checked for phosphates in the RO water getting  0 ppm)

 

 I didn't   use any phosphate reducing media, since I first wanted to understand the cause for such  high values of PO4.

 

After one week, that was just yesterday (April 8th),  the results of the Phosphates tests were the following.  

 

Tests from the "Bowl experiment":

(Ammonia: 1.5)

Phosphates: 0 ( yes, absolutely 0!!)

 

 Tests from the tank:

Phosphates: 2 (yes, definitively still at 2!!)

I see my rocks are still releasing  a huge quantity of phosphates, which makes them unusable in the future.

 

At this point of the story I can say that the rock reincarnation process (which I carried out by following step-by-step the instructions), didn't remove all phosphates absorbed by the rocks.

 

With this  I'm not claiming  that the rock reincarnation process is not able to get rid off phosphates in general, but for sure it didn't work  with my rocks. It surely depended on the rocks (which  were in  my friend's tank for fifteen years) rather the process itself.

 

I decided to open this thread since after my last results, I surfed  on the web to search if someone had the some  phosphates problems after reincarnation rock process.

 

I found this quite old discussion:

 

http://www.marsh-reef.org/marine-and-reef-general-discussion/37822-how-do-i-acid-wash-rock.html  

 

where in #1 opens with:

"But I've read occasional references to "old live rock" that's been in tanks for several years - apparently they may leach phosphates into the water. This is part of the "old tank syndrome" story. (the other part is the aging sand). "

 

while in #5 is claimed:

"Bleach helps sterilize the rock, but acid will actually take off a layer of rock, helps with old rock that may have absorbed phosphates, keep them from releasing it back into the aquarium. Also works with rocks that have been in copper. "

 

I hope that these  my experience  can be useful for some other. But I would like to have your opinions and suggestions mainly.

 

Thank all of you in advance for your attention.