DIY cement rock & Phosphates

my tap water is horrible, not sure on the exact messurments. But I am not worried about it, i am curing my own rock. There is more PO4 in the cement when its curing then what is in the water. I think in the end of the curing proccess it may pick up some PO4, but i think it would be anything to worry about. The only reason i would see a problem with it leaching would be if its going into a established tank. A new tank is going to have issues anyways, and by the time the water cures all or most the PO4 should have leached out. IMO

 

This is something I have been trying to figure out for awhile and on another site they talked about curing the rock in water doing daily changes to remove the phosphates as well as other things. No personal experience though.

 

I was under the impression that PO4 binds into the rock and leaches slowly over a long periods of time

got any links

bump for a few more points of veiw

 

I made my own rock, but cured it in ro/di water. the third batch I made I never even changed the water, just waited until the pH was down to 8.2 and I never saw a rise in Phosphates. The first and second batches I used CC the 3rd I used crushed oyster shells.

 

Ahh HA what I was waiting for some hands on experience with some testing along the way")
So no phos in the oyster shells eh , I have not been sure to use them or not at this point as I realy dont want to have to deal with phos in my new set up as its the reason I have decided to start over. (1st tank ran to long on tap water)

Maybee someone has seen phos rise in their tank after setting up concrete rock? if so would love to here from you

Just trying to get to the bottom of this with tested facts
(the truth is out there) LOL

 

All of my rock is concrete except for a couple of seed pieces. The rock is 5 years old. It has been moved from a 150g to my 210g. I had a problem with a tds meter and read 0 when water was running higher tds from spent di resin into my system. This was enough to start a algae problem that lead me to bleach the tank, yes with the pumps running I poured a gallon of Clorox in the tank. A couple of months later it looked like this



That pic was taken November 8, 2008.

This is a quick pic I took about 5 minutes ago.

 

what did you do with your coral and fish when you did this?(i aslk because I though of doing that myself lol)
how long did you wait to add stuff back in?

 

I left the rock in the tank for 1 week. I then took it out side and let it dry for a week. After that I put it in a 30 gallon container and filled it with water and added Fritz Chlorine Remover. It stayed in the container for 2 weeks then out it came and was washed with a nozzle on a garden hose. I then put it back in the container and let it soak with Fritz for a couple of days.

The coral and other livestock were divided between a 35g, 55g, and two 40g frag tanks. If compare the two pics very few of the corals were in the first pic. Most of the corals I had before the algae died from the algae or attempts to solve the problem. Tech-M was working but at the time I found that out, most of the coal died. We did save a few pieces and they are recovering nicely. The ritteri almost did not make it and the carpet stayed at the lfs for a month. The acro on the far right in pic 2 is from the old setup and has not only recovered well but is now growing up the overflow. The green star pollups and orange zoos are from the old setup and have easily doubled in size.

Part of the reason I nuked the system is I had a plenum under the sand bed in the display that kept being uncovered. It had to go. The skimmer was upgraded also, changed were made to the sump and the return pump too.

This is a pic of the system before the algae.

 

Can't find the links but it was on RC

 

I too read that thread on crushed oyster shell leaching phosphates, and I believe it was a zoo aquarium or someone that passed that info along... However I couldn't find ANY supporting documentation on it. As far as PO4 in DIY rock goes, I had a problem with PO4, and dosed sugar and got rid of it... I then switched tanks using about 50% DIY rock, and never had a problem with it. No PO4 remover used either. Just anecdotal, but my experience nonetheless...

I can't say that it won't release PO4, however, I have known MANY people (One friends tank uses ~1000 lbs of it exclusively)that have used it without anything more than the usual PO4 levels that can sometimes get out of whack due to the usual unknown or speculative reasons...

So what I can add definitively is that the people I have known that use cement DIY rock, have no large PO4 spikes, even over time -just the same po4 problems that can happen to everyone. Also they without exception recommend using it in a reef tank if cured properly.

As far as water source being suspect. I don't think it's an issue because unless there is something to BIND the PO4 inthe rock, it won't leach. And with Ph levels around 12, it's hard to imagine that it would bind to much in that atmosphere. If anything, it will leach OUT of the rock during curing, not after.