The Ultimate DIY Rocks!

[Insane Reefer]

Very cool - thanks for that link, Mr Wilson

This is the link to the recipe itself, for the lazy
http://www.perlite.org/perlite_info...ulating_concrete/general/perlite_concrete.pdf

 

[Neptune777]

<a href=showthread.php?s=&postid=10192090#post10192090 target=_blank>Originally posted</a> by mr.wilson
I found a recipe for prlite concrete on this site. http://www.perlite.org/index.htm

The only selling points they give are light weight and insulative properties. I don't see how this would benefit a reef aquarium. Perlite has no buffering capacity.

Perlite Aggregate=Porous Rocks with less Portland cement=potentially less cure time? I'm not positive but seems logical to me...

I don't think any of the aggregates we add to the MMLR really "buffers" the water since the water ph is not low enough in our display. RHF I believe mentioned this about aragonite and crushed coral etc....

Using this instead of salt will eliminate the salt+cement negative interactions occassionally experienced and also no need to rinse anything away. Besides I think the perlite cell structure would be more efficient at denitrification than the large voids left by rock salt (much more surface area created by perlite)(my theory...not proven).

Besides it's dirt cheap...These are the benifits I can think of on the fly...

 

[Neptune777]

<a href=showthread.php?s=&postid=10192152#post10192152 target=_blank>Originally posted</a> by goldmaniac
I thought this whole thread was using rock salt because it melts away and leaves not only surface area for bacteria, but also holes and nooks and crannies for critters and bugs and 'pods. Perlite wouldn't have this advantage.

Agreed, perlite has beneficial surface area and absorption properties, but if the perlite on the surface never dissolves, the perlite inside the rock wouldn't get sufficient contact with the water, and anyting below the surface is just a lightweight additive. The surface area and absorbtion benefits would only be on the surface-facing pieces of perlite, my best guess.

I think it would depend on your perlite to cement ratios....with lots of perlite I would imagine a very porous rock with lots of very little voids.

 

[Insane Reefer]

This thread has grown beyond just being about salt, Goldman - and it is the best thread I've found for MMLR, hands down.

The idea of the salt was to try to replicate the pores that LR have naturally, and that bacteria live in, however salt voids are hundreds, if not thousands of times bigger than the natural pores in LR. If you have seen microscopic pictures of LR, like the one for perlite the Neptune posted, you could see where perlite would add a more realist environment for our bacteria.

I think that you would almost have to use the perlite in a mix that contains other aggregates (not just salt), mainly OS or CC, or you wouldn't be able to add enough perlite to be effective/worth it, or to keep in on the tank floor.

Just my thoughts...

 

[Azazael13]

My husband is such a geek. I mentioned perlite to him to see what he might know, and the post I had read where the rock floated, and my idea for a mid-column 'island', and he loved it!
LOL
He took it one further, said "Make it a sphere shape, anchor it with monofilament so it doesn't get bashed around and cover it with Green Star Polyps - we could have a 'Death Star!'"
*sigh*

I am really having a hard time finding the fault in this idea. In fact I feel it is made of 100% win and that your husband should continue forward with my full support

Once he gets the creation down to a science I will happily place an order for one :strooper: :strooper:

Imagine rather large (8') aquarium with a few of those. Oh those fish would indeed be strong with the force :strooper: :strooper:

 

[goldmaniac]

Agreed, perlite has much more surface area than holes/voids in concrete. point taken. I didn't think of the microscopic surface area factor. Might get close to the amount of surface area on holes of concrete.

 

[impur]

<a href=showthread.php?s=&postid=10192041#post10192041 target=_blank>Originally posted</a> by Insane Reefer



My husband is such a geek. I mentioned perlite to him to see what he might know, and the post I had read where the rock floated, and my idea for a mid-column 'island', and he loved it!
LOL
He took it one further, said "Make it a sphere shape, anchor it with monofilament so it doesn't get bashed around and cover it with Green Star Polyps - we could have a 'Death Star!'"
*sigh*

lol Brilliant!!!!

 

[Insane Reefer]

<a href=showthread.php?s=&postid=10192227#post10192227 target=_blank>Originally posted</a> by Azazael13
I am really having a hard time finding the fault in this idea. In fact I feel it is made of 100% win and that your husband should continue forward with my full support
:strooper:

LOL - Geek!

This unfortunately would be my project, as I'm the reef/rock geek.

I can just see it - the newest craze in the Reef Hobby - "The Floating Reef".

 

[shookbrad]

I think I will add some in my next batch. I used black lava rock for filter media in my sump for about a year with no problems. I was advised not to but did anyway. I know it has trace elements that we do not want in our reef. When you think about chemistry if our water is a ph around 8 it will not have much effect on breaking down the rocks causing the chemicals to release. If our PH was below 7 then we could have a big problem.

 

[mr.wilson]

<a href=showthread.php?s=&postid=10192184#post10192184 target=_blank>Originally posted</a> by Neptune777
Perlite Aggregate=Porous Rocks with less Portland cement=potentially less cure time? I'm not positive but seems logical to me...

I don't think any of the aggregates we add to the MMLR really "buffers" the water since the water ph is not low enough in our display. RHF I believe mentioned this about aragonite and crushed coral etc....

Using this instead of salt will eliminate the salt+cement negative interactions occassionally experienced and also no need to rinse anything away. Besides I think the perlite cell structure would be more efficient at denitrification than the large voids left by rock salt (much more surface area created by perlite)(my theory...not proven).

Besides it's dirt cheap...These are the benifits I can think of on the fly...

Perlite would require the same amount of portland as an aragonite or oyster shell mix.

Aragonite dissolves at a PH as high as 8.4. While it isn't enough to maintain a heavily stocked tank, localized acidity makes calcium and carbonates bioavailable for microorganisms. Marine organisms will always do better on a calcareous surface. Plastic rocks and non-calcareous rocks have nuisance algae issues, due to the lack of sufficient pro-biotic microbes (bio-films).

The pore structure of cement is better (more surface area) for denitrifying bacteria than perlite. Perlite is more conducive for aerobic bacteria, but there is no shortage of sites for nitrifying bacteria as it is.

As far as cost goes, oyster shell and salt are very accessible.

 

[Insane Reefer]

Neptune, for the sake of comparison, have you priced the appropriate grades of perlite for cost per cubic foot?

 

[mr.wilson]

Where does it say that perlite has more surface area than portland, aragonite, or oyster shell?

 

[Insane Reefer]

Mr Wilson
???

 

[Neptune777]

Just my assumption looking at the microscopic pics...and it's cheaper than aragonite.
I haven't seen anyone complaining about nuisance algea on MMLR over time...where do you get your information concerning live rock promoting bio films over MMLR? MMLR will have the same micro growth over time..

 

[Insane Reefer]

Ok, had a smoke and thought some, and have a thought and a pair of questions.

Thought:
Back-walls made with perlite...

Question1:
Maybe Mr Wilson can answer since he uses plastic hardware a lot, or anyone else can chip in.
Ever seen a plastic/nylon eye screw? I think that is what they are called - screw with a loop on the end?

Question2:
For the fisherpeoples, what is the stealthiest type of monofilament, and one that won't be highlighted by actinics?

 

[Insane Reefer]

Neptune, you misread his post;

Plastic rocks and non-calcareous rocks...

Our MMLR technically counts as calcareous, so I don't think he meant MMLR - just fake stuff and maybe the ceramic stuff?

 

[goldmaniac]

INSANE, I know this thread is covering much more than the topic of salt in MMLR. But with different techniques and ideas, etc. If we find a better raplacement for salt, its wonderful. My point is that we want bugs and 'pods in the rock, and voids from rock salt allow that, where non-dissolving perlite doesn't.

Trust me, if I wanted to hear only about making MMLR with salt, the first 20 pages or so would have been enough.

 

[Neptune777]

<a href=showthread.php?s=&postid=10193066#post10193066 target=_blank>Originally posted</a> by goldmaniac
INSANE, I know this thread is covering much more than the topic of salt in MMLR. But with different techniques and ideas, etc. If we find a better raplacement for salt, its wonderful. My point is that we want bugs and 'pods in the rock, and voids from rock salt allow that, where non-dissolving perlite doesn't.

Trust me, if I wanted to hear only about making MMLR with salt, the first 20 pages or so would have been enough.

That's the real beauty of MMLR...you can sculpt it and add whatever voids you want....regardless of the aggregates. Pods and such will not be in the middle of the rock...that zone is for bacteria and imo perlite is perfect for that (better than rock salt voids)

 

[goldmaniac]

I haven't even put any MMLR into my tank yet, so I do not have any 1st hand experience watching the rock for bugs crawling within. If the voids aren't going to provide cover and housing for critters, then perlite's a good alternative. my stuff is pretty pourus (sp?), and of course everyone's rock is different. I'm still hoping for some copepod real estate when everything Kures.

In the end, it's a Dealer's Choice on the aggregates added to this rock. That's part of the fun. Someone could use Cheetos when making the rock and you'd be hard pressed to tell them with any authority that they're "wrong" to try it.

 

[mr.wilson]

<a href=showthread.php?s=&postid=10193066#post10193066 target=_blank>Originally posted</a> by goldmaniac
INSANE, I know this thread is covering much more than the topic of salt in MMLR. But with different techniques and ideas, etc. If we find a better raplacement for salt, its wonderful. My point is that we want bugs and 'pods in the rock, and voids from rock salt allow that, where non-dissolving perlite doesn't.

Trust me, if I wanted to hear only about making MMLR with salt, the first 20 pages or so would have been enough.

I'm not sure what part of salt (sodium ion or chloride anion) effects the stability of cement. Perhaps another salt would be better.

Calcium chloride (sold as environmentally safe ice melter) may mix better with portland. Calcium chloride is available in large crystals. It's also a common agent used to speed the curing process.

Magnesium chloride (epsom salts) is another cheap salt that's readily available, and safe once dissolved.