Marco rock and phosphate

[thetman36]

Has anyone else had an issue with Marco rock leaching phosphate. this is a continuation of my last post asking about removing phosphate. I have a 210 gal reef tank total water volume 300 gal. It started with dead sand and marco rock. No live rock was used in this tank. the tank has been running over 3 months. I have not over fed. I am running a refugium with macro algae. I have tested my ro water it has zero phosphate. My salt water holding barrels also test negative for phosphate. I have done many water changes the last being two 50 gal water changes 3 days apart. I am still getting phosphate readings and algae growth all over the tank including the sand bed. I can only infer that the sand and rock is leaching phosphate. Any thoughts.? yes I am running my skimmer round the clock. I am running a uv sterilizer. flow in the tank is high I have an mp40 and mp60 turnover rate is abut 7X per hour. I did notice an increase in algae as soon as my pacific sun led lights came on line. before that I was not running much light in the tank at all. I have been advised to lower the time of the light exposure and to turn down my red green and orange channels to lower algae growth. But still not sure of the source of the phosphate. I started running carbon and kents phosphate removal media about 4 days ago. I am still seeing the same level of phosphate. I am getting a reading of about .1 to .25 on the salifert test chart. Hard to tell the exact color with this test kit it is closer to .1 but over .03 and will not budge any lower. so I think it must be coming from the marco rock. I am going to remove a rock and put it into a bucket of fresh mixed salt water and see if it is leaching over a week time period. I am at a loss here.

 

[thetman36]

just a note i am going to buffer my ph which is now at 8 to 8.3 I have been told this may help stop the rock from leaching.

 

[dherrera83]

Are you running GFO? If not you should. That can help. Look it up on bulkreefsupply.com that where i get mine.

 

[thetman36]

when the media i am using from Kent runs out I will try the bulk reef GFO

 

[dherrera83]

how long are you running your lights?

 

[thetman36]

sunrise starts at 6:30 am lasts for 120 min lights stay on till sunset which starts at 6:30 and lasts 1 hour so 12 hours of light each day.

 

[ecvernon]

I have hade Marco rocks and they leach phosphate just like any other rock. IMO you will see leaching unless you let it cure at least a month with no live stock. Either way running some type of phosphate removal is nessecary. It will continue to leech and you will need something to soak it up. Also you need to get a Hanna phosphate checker. The color results are so hard to read.

 

[JonnyJ]

Bottom line

Run gfo and rapidly change it when exhausted using a Hanna checker.

Next run a large fuge with lots of macro - the key is to continuously harvest it weekly/biweekly.

Continuous water changes

And wait..,


I went through this for around 5 months. Trying with just waterchanges


Fuge and gfo did the trick

 

[Imbarrie]

I had a similar issue with a large piece of dry Pukani rock through BRS that was growing cyano like crazy and I had elevated levels of phosphates.
I took the rock out and gave it a 10 minute bath in muriatic acid and then rinsed it for two weeks in fresh and RODI.

Its been back in the tank for two weeks and no new signs of cyano, I will be testing tonight.
You can try cycling it with water changes and GFO but that will take months. Maybe up to a year.

 

[ecvernon]

I had a similar issue with a large piece of dry Pukani rock through BRS that was growing cyano like crazy and I had elevated levels of phosphates.
I took the rock out and gave it a 10 minute bath in muriatic acid and then rinsed it for two weeks in fresh and RODI.

Its been back in the tank for two weeks and no new signs of cyano, I will be testing tonight.
You can try cycling it with water changes and GFO but that will take months. Maybe up to a year.

Curious how long did you cycle it before putting it into your tank? I currently have some pukani rock cycling and plan on swapping out some. I plan to have it cook for two months

 

[Imbarrie]

Cook for two months?
It's dry rock and would not need a cycle to process any kind of die off. If you are trying to leech phosphates through a cycling process I think you will find two months to be too short.
There is a process to fix phosphate a lot faster. Lanthanum chloride.

 

[ecvernon]

I think dry rock should in fact be cycled to process dead organic material in the rocks.( not die off since its dry)
I meant cook as in term used to say cycle rock in separate container with heater, power heads, and no light.
I am deciding to go two months based on my previous experience with Marco rocks and dry rocks from reef cleaners.org. I would change the water in the containers with saltwater from my water changes of my display tank. For weeks the water was discolored and smelled bad even after the water changes. That lasted a few weeks. I planned on doing it a lot longer because the BRS pukani rock has a lot more organic debris. The difference between the rocks is very visible. In comparison Marco rock could be called clean. I've heard of using acid but I was hoping to do it naturally being that I will be slowly swapping rocks over the next few months. I understand that there will be phosphates leached but if I swap one rock at a time I expect it to be of little effect while running GFO. Thanks

 

[thetman36]

ok so I added a phosphate sponge for two days phosphates came down. My fuge with macro is bursting I have to harvest it almost every week. So Marco rock is not as clean as i was hoping it would be. Oh well I guess I will be going through gfo and water like crazy because my fish are in and no other place to put them. Oh my test with marco rock in ro water it is leaching phosphate for sure. My tank cycled for 3 months with the maro rock and sand prior to this. I hope i only have 2 month of leaching left. If 5 moths is the time frame.

 

[thetman36]

I am doing a 50 gal water change on my 300 gal tank every week not all at once but 15 gal one day then another 15 gal 3 days later etc. I am switching out my socks every 3 days clean or dirty. I am replacing phosphate sponge every 48 hours and have more phosphate removal media running in a reactor. my fuge with macro is doing well. I do see small amount of cyano but cleaning it out when it appears. not much cyano at all really. I guess it's all part of a new tank syndrome. keeps me busy for sure.

 

[ChrisB]

I had same prob with dead marco rock . Lfs store hear was telling of customers that had same prob. I had done a large wc ,added gfo reactor, pulled gha off rocks as much as I can and the last thing I did was actually got a brush an scrubbed the rock clean which skimmer took care of.