po4 from Marco rocks.
- Thread starter CrazyEyes
- Start date
BigJohnny
Active member
Great good luck moving forward!
...
There have been posts for years about the problems with Marco rocks...
BigJohnny
Active member
interesting, everyone I have ever spoken to has had absolutely no issues (I have only spoken to about a dozen people but all had zero issues). Pukani I have seen how much organic material you have to remove, my marco rock is spotless and colorless. I'd also be curious to know if all those people complaining of problems tested their rocks beforehand outside of their tank to eliminate all other variables. water source could also be high in phosphates, even with an rodi(not functioning properly).
Not saying it's not true I personally have just never heard that until now.
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BigJohnny
Active member
Ok so I just did hours of research and I have concluded it's a crapshoot. Equal # of success/failure accounts and that actually leads me to believe a greater number of successes because people who are having problems are more likely to start a thread like this one. You don't see many, "marco rocks didn't leach phosphates" threads. It can also vary greatly by batch. What's funny though is the people who do have success and no significant algae problems have done so over and over again with marco rocks. One guy 6 times over last 8 years (all he does is pressure wash and soak in vinegar water for 1 day) That leads me to believe cuc/husbandry/proper feeding/nutrient export are equally if not more of a deciding factor of whether it will cause problems for people. I am not saying that this is necessarily the case in this instance (could be a bad batch).
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The expert who said, "rocks do not leach phosphate but organic matter that's on them could" is not entirely accurate. Obviously rock like Pukani has a ton of organic matter on/in it and is why many people report high phosphates.
Marco rock, however, doesn't have a lot of organic matter. It's pretty damn clean rock. So where is the phosphate coming from? It's in the water. Florida is rich in phosphate (we supply 60% of the phosphate used by America), phosphate is in our water, the water was flowing through the rock, as the rock dried the rock absorbed the phosphate and when we rehydrate it by putting it in our closed systems the phosphate leaches out of the rock. No different than if we took a bucket of saltwater and let the water evaporate. We would be left with salt and whatever else was in the water. Refill the bucket and the specific gravity will be above 1.
http://www.floridaphosphate.org
Marco rock, however, doesn't have a lot of organic matter. It's pretty damn clean rock. So where is the phosphate coming from? It's in the water. Florida is rich in phosphate (we supply 60% of the phosphate used by America), phosphate is in our water, the water was flowing through the rock, as the rock dried the rock absorbed the phosphate and when we rehydrate it by putting it in our closed systems the phosphate leaches out of the rock. No different than if we took a bucket of saltwater and let the water evaporate. We would be left with salt and whatever else was in the water. Refill the bucket and the specific gravity will be above 1.
http://www.floridaphosphate.org
GatorAlum05
Member
All dry rocks leech po4
BigJohnny
Active member
Yes I was not aware of this until a prior poster said the same thing. However, the extent to which a certain brand of rocks (even from florida) leach phosphates, and the impact on a new tank cannot be generalized. Every vendor, batch, and rock is different. Regardless of where you get it from, it's really a roll of the dice as to how much they leach if any, and whether or not it will cause you issues. The quarry where the rock is mined from, how old it is, how much water flow came through it, how it was treated/stored after mining etc. all have a significant impact. The tank set up/husbandry is another variable as to whether the effect of said leaching is noticeable or problematic for each individual.
Cuzza, have you actually used marco rock or just chiming in based on research (just curious)?
Update, the last 5 people I've talked to have had 0 problems with marco rock and hair algae/excessive phosphates. One has used it 3 times. Currently you have a better chance of not having issues than having issues according to my extensive forum/google research (whatever that means haha)
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BigJohnny
Active member
what exactly does cook mean?
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BigJohnny
Active member
Well I've heard people use the term "cook" in many different ways. Soak in freshwater in the sun, soak in saltwater in the sun, soak in vinegar water in the sun, soak in acid, and all of the above indoors as well with normal or higher temperatures.
MizTanks, since uve had so much success (even with pukani) I'm curious how you meant it. Could you outline your process in detail for us please? I think I will follow your method just in case!
BigJohnny
Active member
MizTanks, would love to hear your process still but just thought I'd repost this post from 3 years ago from someone who sounds like they know what they are talking about:
From the standpoint of phosphate leaching, there are a couple of considerations. If the rock was originally in the sea (as opposed to terrestrially-mined fossilized reef rock), then it probably doesn't have much if any phosphate in the actual rock matrix. In this case, dissolving the outer few millimeters of the rock's surface should remove any phosphate that may have precipitated during the time the rock was in an aquarium with relatively high tank water phosphate concentrations.<br />
<br />
If the rock was terrestrially mined, then there's a chance that you might have a good bit of phosphate in the rock itself that's accumulated over the eons of groundwater penetration that the rock was exposed to. In this case, removing the outer surface may not have all that much effect on phosphate leaching potential since "new" surface is exposed that contains phosphate.<br />
<br />
Under this last circumstance, you've a few choices that could be used to leach the phosphate out of the last few millimeters of the rock's surface. The first would be to place the rock in a trash can, and circulate heated seawater for a few weeks. That will dissolve phosphate on the rock until equilibrium is reached with the water. It would probably be enough just to change the seawater every week or so to remove the phosphate being leached and "make room for more" in the water. But you can also add an absorbent/precipitater to lock up the phosphate and encourage dissolution from the rock. Many folks do this with lanthanum chloride (SeaKleer), but you could also accomplish it by adding a fair amount of GFO in a mesh bag.<br />
<br />
However, if you're the patient type, you could just aquascape your tank, add your seawater, run the tank without illumination for a few weeks, and include a GFO reactor. Water tests with the Hanna 713 phosphate checker will tell you whether the rock is leaching phosphate into the water, and the lack of illumination will prevent your tank from becoming an algae farm.
From the standpoint of phosphate leaching, there are a couple of considerations. If the rock was originally in the sea (as opposed to terrestrially-mined fossilized reef rock), then it probably doesn't have much if any phosphate in the actual rock matrix. In this case, dissolving the outer few millimeters of the rock's surface should remove any phosphate that may have precipitated during the time the rock was in an aquarium with relatively high tank water phosphate concentrations.<br />
<br />
If the rock was terrestrially mined, then there's a chance that you might have a good bit of phosphate in the rock itself that's accumulated over the eons of groundwater penetration that the rock was exposed to. In this case, removing the outer surface may not have all that much effect on phosphate leaching potential since "new" surface is exposed that contains phosphate.<br />
<br />
Under this last circumstance, you've a few choices that could be used to leach the phosphate out of the last few millimeters of the rock's surface. The first would be to place the rock in a trash can, and circulate heated seawater for a few weeks. That will dissolve phosphate on the rock until equilibrium is reached with the water. It would probably be enough just to change the seawater every week or so to remove the phosphate being leached and "make room for more" in the water. But you can also add an absorbent/precipitater to lock up the phosphate and encourage dissolution from the rock. Many folks do this with lanthanum chloride (SeaKleer), but you could also accomplish it by adding a fair amount of GFO in a mesh bag.<br />
<br />
However, if you're the patient type, you could just aquascape your tank, add your seawater, run the tank without illumination for a few weeks, and include a GFO reactor. Water tests with the Hanna 713 phosphate checker will tell you whether the rock is leaching phosphate into the water, and the lack of illumination will prevent your tank from becoming an algae farm.
BigJohnny
Active member
Also I trust everything this guy (one on the right) from brs says. He always gives the facts and recommends alternatives even if it means purchasing stuff from somewhere besides brs, and that tells me he's not externally motivated (ofcourse they show products they sell to sell them but you get what i mean). He has 30 years of experience I think. Here is his video on curing, although doesn't even discuss leaching phosphates from the rock itself, however said he had never had any problems curing this way
https://youtu.be/qrNSssUarA0
https://youtu.be/qrNSssUarA0
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Flippers4pups
Home made abyss
Bought a hundred pounds of Marco rocks for my current build back
Two months ago. Once I got it, it was as clean looking and very porous. Placed all of it in saltwater, powerhead and a heater. Waited two whole weeks before testing for PO4 and tested every week for a month. Results: no PO4, zero.
I was very aware that this type of rock can absorb anything in the water and made sure that the water was void of everything. I changed all my RO/DI filters prior to placing the rock in the water.
Been cycling the tank now for a month and nearing the end now. Still no PO4.
I too think it's a crap shoot with this type of rock.
(Side note): I did look all over many different forums for pictures of this rock from years back to compare what it looked like then to what I got. With this comparison it was clear that they must be acid washing prior to selling it now. Back in 2010 for instance, it looked way more solid and not as porous.
Two months ago. Once I got it, it was as clean looking and very porous. Placed all of it in saltwater, powerhead and a heater. Waited two whole weeks before testing for PO4 and tested every week for a month. Results: no PO4, zero.
I was very aware that this type of rock can absorb anything in the water and made sure that the water was void of everything. I changed all my RO/DI filters prior to placing the rock in the water.
Been cycling the tank now for a month and nearing the end now. Still no PO4.
I too think it's a crap shoot with this type of rock.
(Side note): I did look all over many different forums for pictures of this rock from years back to compare what it looked like then to what I got. With this comparison it was clear that they must be acid washing prior to selling it now. Back in 2010 for instance, it looked way more solid and not as porous.
BigJohnny
Active member
Thanks for your input! Def puts me more at ease about mine! I was told they now powerwash, bleach, then acid wash. Most people had problems pre 2010-2012 according to my research as well.
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