How much Aluminum will it leach? Let's guess

[Turbo's Aquatics]

Interesting....

 

[FarmerTy]

Thanks for the clarification!

I would hypothesize that it will take some time for the denitrifying bacteria to colonize the block to aid in the breakdown of nitrates... a little more now that you had recently moved and rinsed the block when swapping sumps.

 

[jason2459]

Sorry, going to repost so it's at top of a page.

Conclusion and Summary:
The understanding from the manufacturer is that the MarinePure media does not leach any Aluminum into fresh or saltwater systems. That it is completely inert, is 100% safe, and will not alter the aquarium's chemistry at all.

http://www.cermedia.com/marinepure-faq.php

From the FAQ:
"What is MarinePure made of and will it leach anything into my water?

MarinePure is an inert aluminosilicate ceramic that has been fired over 1000°C. It will not leach into tank or pond water."

"Will MarinePure ROCK affect my water chemistry?

No, MarinePure ROCK is made from an inert ceramic. It has no effect on the water chemistry. One caveat, it also does not add beneficial calcium that some reefers desire."

Lets start with some basic before numbers of which I was going into it just concentrating on Al and not so much the nutrients PO4 and NO3 as I did not and have not had issues with either of them and they were already to low for my taste.

Before adding the block:
PO4:
Hanna 736 ULR: 3ppb and 0.009198 ppm converted
Triton: 3.15 µg/l and 0.010 mg/l converted

Nitrates:
Red Sea/Salifert/API/Nyos: 0 (undetectable)

Al:
Triton: 0 µg/l (has been under 2 µg/l, Triton's set point, in every test result from Triton I've done)

After 1 month with the block in place:
PO4:
Hanna: 5ppb Phosphorus or 0.01533ppm Phosphates converted.
Triton: 6.59 µg/l and 0.020 mg/l converted

Nitrates:
Red Sea/Salifert/Nyos: ~2.5mg/L

Al:
Triton: 19.15 µg/l (do not know what form this is in fyi)

During this entire month I maintained my vinegar/vodka dosing, skimming, and 1% daily water changes. I did not run or use anything else that could export anything.


After taking the sample water for Triton I placed in the Marine Pure block in my sump in a low flow area. Several odd events occurred the following day and days after that. Which for my tank change is very easy for me to see as I note pretty much any change I do to my tank since I stood it up in a tank journal and any reactions my tank has. I feel I've gotten pretty good at observations of cause and effect in my system but at the same time know there is room for error and of course always learning.

Effects that were noted after placing in the block:

1. Fiji Leather Coral quickly looked irritated and shrunk
2. Duncan retracted
3. One of my Bubble tips split (otherwise they looked great the entire time)
4. A single drastic short term drop in pH
5. All my sponges "shed" and shrunk

My Fiji Yellow Leather has not had full polyp extension the entire time the block was in place. It took over 2 weeks before it would start looking somewhat ok. The Duncan recovered fairly quickly. The sponges slowly started growing again.

Some of that I believe can be explained by a quick large growth of bacteria in the media (Duncan retracting and quick pH drop). But the longer term effects on the Fiji Leather I believe are more directly related to the Block and the Al content. I still don't know about the sponge if its directly but at least is indirectly related.

After this one month period I did move all my sump equipment to a new location and sump. I also went ahead and moved the MarinePure block over a couple days after the sump was already running doing a quick rinse in tank water from the old sump. I believe this swishing and draining of the block exported quite a bit of bacteria and the act of moving it released some more fines from the media it seems as I noted the following again after placing the block in the new sump.

1. Fiji leather Coral quickly looking irritated and shrunk.
2. Duncan retracted
3. A single drastic short term drop in pH
4. All my sponges "shed" and shrunk

I do not believe it to be coincidence but a direct relation to placing the Marine Pure block into the system.




As a side note there was one other unexpected event that occurred. Which was my Nitrates increased during this time. My phosphates did also slightly but with in what they normally trend. My nitrates trended much higher then normal in the after results.

Link to that post when I found my nitrates increasing including a chart showing the ramp up.
https://www.reef2reef.com/threads/h...t-leach-lets-guess.247034/page-8#post-2962938

Just found it interesting and humorous but not concerning as this is also in the manufacturers FAQ. I did have the block in a low flow area...

"I know MarinePure is effective at removing Ammonia and Nitrites, but will it remove Nitrates?

MarinePure Blocks do an excellent job in supporting bacteria which remove ammonia and nitrite. Bacteria based Nitrate removal is a little more difficult as it is very system dependent. Any media for this purpose needs to be in an anoxic environment (very low oxygen) and have a carbon source available. These conditions are dependent on systems bio-loads and flow rates. Our blocks are thick so the oxygen in the water passing through the block can be consumed before entering the middle of the block. We recommend placing the media in a passive or low flow area for the best opportunity to remove Nitrates. "

 

[jason2459]

Interesting....

Ha! yes, very.

 

[jason2459]

Thanks for the clarification!

I would hypothesize that it will take some time for the denitrifying bacteria to colonize the block to aid in the breakdown of nitrates... a little more now that you had recently moved and rinsed the block when swapping sumps.

And to clarify more. The block is just an add on to my current system. My current system handles nitrates very very well. I decided not to stop my 1% daily water changes, vinegar/vodka dosing, and skimmer as they are the main components to keeping my system that way. I also understand that keeping that online would potentially reduce the Al content. But it's also what I've done in the past during other Triton tests showing under their set point.

I do have a Turbo Aquatics ATS and believe Algae is very important to a system but went offline several weeks before this month period and is coming back online now. No, I do not think it contributed to the increase in Nitrates as I've gone several periods in the past with out harvesting algae with 0 rise in nitrates. I just feel harvesting Algae in some way helps make a complete and healthy system.

 

[andrewey]

Great experiment- really top notch stuff here depicting real world conditions (which even though less scientifically ideal than completely controlled experiment, is probably more applicable to hobbyist and as good as it's going to get for the time being). Obviously one could put a MP block in a few tank with a heater and powerhead (previously colonized by aerobic and anaerobic bacteria) vs a couple control sand send the results to triton, but who's going to spend the money on that?

I agree that the MP is probably acting as a nitrate factory early on until anaerobic bacteria colonize in suffient numbers. Really great write up and results!

 

[FarmerTy]

So for discussion of what we can draw from this:

-it seems apparent that they leach some Al, in what form is unknown for now.
-pre-rinsing is critical before putting it in your tank
-leathers seem somewhat irritated at the addition of these blocks but seem to recover
-concentrations as high as 85 ug/l of Al have no observable effect on at least my SPS-dominant tank

 

[jason2459]

FWIW, I will most likely be doing another Triton test for some other curiosity thing I may end up doing with in the next 6 months. I'll make sure to update this thread with those results whenever I end up doing it.

 

[reef_ranch]

And the Al may have been higher if I didn't do 1% daily water changes and skimmer turned off which exported about a cup a day.

As for nitrates, I did not expect any increase at all. My system has been up since 2009 and has maintained very low and undetectable nitrates almost the entire time. Even when I have had high PO4 problems.

I wouldn't have expected an increase in nitrates either, but don't understand how the block could have contributed to an increase. Could it have killed off bacteria? Or is it more likely that some other factor caused the increase?

 

[FarmerTy]

FWIW, my Al concentration was 84 ug/l in 2014 and 85 ug/l in 2015 with no water changes in that timeframe. I had two blocks in the sump the entire time during that period if I remember correctly.

I would dare to say there is either a terminal point of leaching for the blocks or a max concentration the tank will appreciably allow due to other unknown factors.

I will be submitting another Triton sample in the Fall and can update my results as well if it is useful to others.

 

[FarmerTy]

I wouldn't have expected an increase in nitrates either, but don't understand how the block could have contributed to an increase. Could it have killed off bacteria? Or is it more likely that some other factor caused the increase?

I would presume since the block was probably colonized by nitrifying bacteria very quickly, that it aided in converting ammonia/nitrites to nitrates more rapidly than his system had processed it before, hence the gentle rise in nitrates.

Once colonized by denitrifying bacteria, I'd imagine that nitrate level would swing the other way.

 

[jason2459]

I wouldn't have expected an increase in nitrates either, but don't understand how the block could have contributed to an increase. Could it have killed off bacteria? Or is it more likely that some other factor caused the increase?

What I'm thinking.

I believe bacteria grew with in the block very rapidly and by quite a lot as indicated by the sudden pH drop after placing it in the sump. The bacteria that would have occupied the block should be facultative anaerobes as I believe it was most likely mainly driven by my carbon dosing. This means they can switch between being aerobic and anaerobic as needed so they would be very efficient at reducing Nitrates.

But, if they are in there not getting exported or being re-consumed slower then they die off before they have a chance of denitrification would release back Nitrates. Which is where that nitrate factory comes in. No real idea though on this last part. I don't believe this last part is happening. Otherwise it would be happening all the time in my live rock.

 

[silvernblackr35]

Interesting thread, I might have missed this but has anyone suggested maybe curing the blocks in saltwater prior to adding them to the tank? Would be interesting if we could get a time frame of when the aluminum stops leaching, if it stops at all.

 

[jason2459]

Interesting thread, I might have missed this but has anyone suggested maybe curing the blocks in saltwater prior to adding them to the tank? Would be interesting if we could get a time frame of when the aluminum stops leaching, if it stops at all.

Considering the entire media is Al based I would assume it will leach until it's fully dissolved. Many have noted it gets softer as it ages.

 

[reef_ranch]

What I'm thinking.

I believe bacteria grew with in the block very rapidly and by quite a lot as indicated by the sudden pH drop after placing it in the sump. The bacteria that would have occupied the block should be facultative anaerobes as I believe it was most likely mainly driven by my carbon dosing. This means they can switch between being aerobic and anaerobic as needed so they would be very efficient at reducing Nitrates.

But, if they are in there not getting exported or being re-consumed slower then they die off before they have a chance of denitrification would release back Nitrates. Which is where that nitrate factory comes in. No real idea though on this last part. I don't believe this last part is happening. Otherwise it would be happening all the time in my live rock.

What would be the driver for a sudden bacteria growth? Its not likely that they were substrate/surface area limited since your nutrient levels were already so low. That suggests that the population of bacteria you had was sufficient to process the ammonia and nitrogen inputs to the tank.

Your conclusion appears based on a sudden decrease in pH. But I'm not sure you can confidently conclude that the ph drop was caused by an increase in bacteria population, it may have been something to do with the aluminum fines. Randy's article on the effects of aluminum on leather corals observed a reduction in pH (from 8.35 to 8.25) when he dosed aluminum.

I don't think you can really draw any conclusions regarding bacteria behavior from your experiment -- at least so far. Do you plan on keeping the block in the tank long term? Other than for the science of it, I don't see why you would -- you don't need the nutrient reduction function and your leather coral will be happier without it.

 

[jason2459]

What would be the driver for a sudden bacteria growth? Its not likely that they were substrate/surface area limited since your nutrient levels were already so low. That suggests that the population of bacteria you had was sufficient to process the ammonia and nitrogen inputs to the tank.

Your conclusion appears based on a sudden decrease in pH. But I'm not sure you can confidently conclude that the ph drop was caused by an increase in bacteria population, it may have been something to do with the aluminum fines. Randy's article on the effects of aluminum on leather corals observed a reduction in pH (from 8.35 to 8.25) when he dosed aluminum.

I don't think you can really draw any conclusions regarding bacteria behavior from your experiment -- at least so far. Do you plan on keeping the block in the tank long term? Other than for the science of it, I don't see why you would -- you don't need the nutrient reduction function and your leather coral will be happier without it.

Yes, my current population of bacteria going into this was sufficient to help maintain low levels of NO3 and PO4. I do believe though that the block is extremely well suited to house bacteria and lots of it. edit: which is what confuses me on why the NO3 went up.

Yes, you are right I am assuming and don't think I've tried to state it as fact. The sudden drop in pH IME though has corresponded to quick increase of bacterial growth or addition. But yes it's possibly something else.

I do plan on keeping the block in for a bit longer. Because I am curious and there's lots of stuff I don't need.

 

[jason2459]

So, this pH event happened twice and both times right after putting in the block. My belief holds that it's due to a sudden increase in bacterial count.

 

[jason2459]

One thing I could do is add some bacteria and see if I get the same results. I have several bottles of bacteria in a bottle I bought to see what was in them seen here:
Starting at post 179
https://www.reef2reef.com/threads/our-tanks-biology-up-close.239838/page-9

Since I will be adding it directly I should see the drop fairly quickly and not over night like with the marine pure events seen in the above chart. I would use the EcoBalance as thats the one I saw the most active and live bacteria in.

 

[jason2459]

FWIW, this nitrate, bacteria, pH thing wasn't the initial intent of this thread at all, also stated that in the very first post, and didn't think it would come up at all. But this is to much fun and will continue down this new path now that the Al leaching thing is out of the way.

 

[jason2459]

Any thoughts on anything @Randy Holmes-Farley