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Using Dolomite

24K views 106 replies 15 participants last post by  GrampsGrunge 
#1 ·
So I have this stuff, and I wonder if it can be used as substrate alone or should it be mixed into a substrate. I have some in a jar of water now. It is small dark grey pellets.


 
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#2 ·
Forget using it as substrate alone...it dissolved into muddy brown water. So the gravel sized rock that is used in road construction would be a better choice for substrate. Aragonite and crushed coral is another way to go about this from what I've heard. But dosing an aquarium with the form pictured in the first post seems possible. Dirty, but possible.
 
#9 ·
I was looking at the bag and missed that. I was wondering where this info comes from. Also if it doesnt harm terrestrial plants I wonder how much danger there really is to aquatic plants? If there is a resin coating then fish and inverts may be harmed but plants I have doubts. I tend to think the rise in ph, gh, and kh would be the bigger danger if overdosed.
 
#5 ·
I find that lime number terrifying for some reason. I have no idea what lime would even do in a tank environment. I've worked with this kind of stuff around the yard due to acidic soil and it's never pleasant. I've never used pellet form so maybe it isn't as bad, but the powder is awful.

I'm not here to tell you what to do. It does seem as though the all mighty miracle of Dolomite and the perfect formula to use is being kept secret. Crushed coral is easy. I have Aqua Clear HOB's, so I added a tiny amount to the 10 gallon in a filter bag and a slightly larger amount to the 29, also in a filter bag. If I didn't buy crushed coral, I would have bought substrate for cichlid tanks. It is made specifically to bolster pH and water hardness. It's also tank safe, so no fear of what might happen when something that typically is not found in a fish tank is introduced.

Good luck!
 
#15 ·
I find that lime number terrifying for some reason. I have no idea what lime would even do in a tank environment. I've worked with this kind of stuff around the yard due to acidic soil and it's never pleasant. I've never used pellet form so maybe it isn't as bad, but the powder is awful.

Good luck!
It stinks too. I can imagine you need a respirator when using the powder. I have no clue how this will turn out, but since I had the lime on hand and the subject came up...why not?
 
#6 · (Edited)
I don't know what type of resin is used to coat these pellets, but I hope it's not poison to me or my fish and plants. I poured .5 cup (I wrote 1 cup earlier, but I read the lines on the jar wrong) of the muddy water into the 20 gallon planter pond. It was already at 7.6 pH. So will it go down or up with this stuff? Will the GH be off the charts? Will the KH go off the charts too? I suspect it will.




 
#7 ·
Ive used limestone in my cichlid tanks. The lime I used was large rocks from a limestone quarry that I used as decorations and caves, think Texas holey rock without the holes. The most notable effect, and the reason I used it, was a ph change from out of the tap at 7.8 to 8.6 in tank.
 
#10 ·
Ouch, that is taking the pH in the wrong direction for my fish and plants, I think. My understanding is that plants do well in low pH, not high. I now have to consider using Baking Soda? Yuc, more stuff. But, didn't I see a lot of carbon in the analysis? Maybe that will keep this type of Lime from raising the pH too much. I need a chemistry tune-up.
 
#11 ·
I think lime like this might be really useful to pre-charge kitty litter or safe-t-sorb.
 
#12 · (Edited)
Or coir (coconut husk/bark). Coir binds calcium from what I have read. I really don't know what the ramifications are from calcium binding substrates. Is it available to plant roots touching it? Would there be less calcium in the water column? Was the ratio mentioned in another post as important 4-1 mg/ca or ca/mg? I'll have to check.

It is 4:1 Ca:Mg according to other posts.
 
#16 ·
I think this is a great experiment. Dolomite is different than lime. For example dolomite will not interact with acids like limestone does. Dolomite is a much much harder stone than limestone. With that said the ph changes associated with limestone may not be as dramatic as with limestone.
 
#19 · (Edited)
I was looking at some of the dietary dolomite powders and they are about a 2:1 ratio.
I have been doing some research and where i think the benefit of dolomite comes in is the magnesium plays a role in the plant processing of nutrients and the creation of enzymes. Having the magnesium available to the roots in the substrate as opposed to free floating the water column may work nicely. This is of course assuming the magnesium in dolomite is readily processed by the plants, I havent got this far in my research yet.

How about this experiment awolf. Dissolve your dolomite in ro/di water and measure ph. Start soaking a clay source such as sts or cat litter. One the ph stops dropping and stabilizes drain the water from the clay source and dissolve another batch of dolomite in ro/di water and soak the clay source again. Do this process until the ph stays stable as that should indicate (in theory) that the clay has absorbed as much dolomite cations as possible. Use the clay as a substrate under or mixed with dirt and capped with sand.
 
#27 ·
From my gardening memory, I think dolomite breaks down clay converting bad soil into a better quality platform for plants to grow in, and interacts with composted areas in a different way, converting it into a benign medium. Think it would be better served in the substrate rather than floating about
 
#28 ·
I suspect our problems with, and questions about "dolomite" are largely due to the term "dolomite" being ambiguous. There is the mineral dolomite, there is the garden additive dolomite, there is the dietary supplement dolomite, etc. and they aren't the same stuff. Back in the 50's when I was in college I was a spelunker - a cave explorer. That is when I first ran into the word "dolomite", since most Missouri caves were formed in rocks which were called that. I did a lot of reading to find out what that word meant. As I recall, dolomite is not a specific molecule, as calcium carbonite (CaCO3) is. Dolomite is a mineral, just as granite is. It is made up of various ratios of calcium carbonate and magnesium carbonate. The two molecules link up on a crystal level, not as a molecule.

So, when we go to a rock/gravel seller and buy their dolomite gravel, what we get is not something with a specific ratio of calcium and magnesium. When we buy a dietary supplement called dolomite, what we get could be a mix of a lot of stuff, some of which is probably calcium carbonate and magnesium carbonate. And, when we buy a bag of dolomite for our garden, what we get is what the seller thinks is good for our plants and their profits.

Perhaps I'm wrong about this. If so, I'm confident that some of you will let me know:wink2:
 
#31 ·
@Hoppy You have been doing this a long time and have done a lot of experimentation so let me ask this question and keep it in terms of heavy root feeds for now. Do you think there is any benefit to using CaMg(CO3) in the substrate lets say locked in to a high cec sub or additive like sts as opposed to using MgSO4 dosed in the water column? I guess I am curious from the point of this discussion what happens chemically to the mg forms we dose in our tanks specifically do the mg compounds break down and if so what happens to the sulfates? I realize in a high tech tank the sulfate compounds may be more in demand than fish food can supply. In a low tech tank that may not be the case and the calcium may be more beneficial.

Lets move to stems for a second. My tanks are low tech and as of now I only dose excel with no ferts. I have a substantial growth of L. Repens and I mean substantial to the point they need trimmed as they are growing across the top of the water now they are so tall. The stem 'roots' (whats the official term for stem roots?) get long on this stand of L. repens. It seems to me if I provided additional nutrients in the substrate in a significant quantity the plant would grow fewer of these stem roots as it is getting more nutrients from the substrate. It also seems to me that the nutrients I need to provide would be a form of mg and ca. Since I use clay based soils that are red I make the assumption that I am providing enough iron in my low tech environment. I make that assumption based on my roseafolia stays fairly red even in low light. I dont know maybe I am barking up the wrong tree here and am way off base which is why I am asking. I also figure this also points to the ideas about mineralizing soil. I also wonder lets say we sprinkle a substantial quantity of a nutrient mix, any nutrient really, under a high cec product like sts, cat litter, or turface placing it diectly on the base of the aquarium. We also precharge the high cec material with the same nutrient mix and place it over the bottom. Use a high clay content soil over the sts or whatever. Plant heavy from the get go. How much of our nutrients end up loose floating in the water column as opposed to staying in the sub/soil? Will the sub and cap act as a barrier and keep them out of the water column?

My wife tells me I over think things lol. Reading this post I tend to agree with her but hey inquiring minds want to know!!
 
#33 ·
@Hoppy You have been doing this a long time and have done a lot of experimentation so let me ask this question and keep it in terms of heavy root feeds for now. Do you think there is any benefit to using CaMg(CO3) in the substrate lets say locked in to a high cec sub or additive like sts as opposed to using MgSO4 dosed in the water column? I guess I am curious from the point of this discussion what happens chemically to the mg forms we dose in our tanks specifically do the mg compounds break down and if so what happens to the sulfates?
All of the simple chemicals we use for nutrients become ions in water. The MgCO3 becomes Mg++ and CO3-- ions in the water. Dolomite becomes stew of Ca++, Mg++ and CO3-- ions in water. Unless there are other ions in the water, which form insoluble compounds with any of those 3 ions, none of the ions is ever locked up and unavailable to the plants. And, MgSO4 becomes Mg++ and SO4-- ions, also always available. When a plant takes up one of those ions to use as food, that ion is replaced in the water by a different ion from the plant, which I don't recall, but it is a simple one like H+.
I realize in a high tech tank the sulfate compounds may be more in demand than fish food can supply. In a low tech tank that may not be the case and the calcium may be more beneficial.

Lets move to stems for a second. My tanks are low tech and as of now I only dose excel with no ferts. I have a substantial growth of L. Repens and I mean substantial to the point they need trimmed as they are growing across the top of the water now they are so tall. The stem 'roots' (whats the official term for stem roots?) get long on this stand of L. repens.
Those are aerial roots, and they are not there to pick up nutrients from the water, but to anchor any piece of the stem if it breaks off and floats to another location. The amount of aerial roots seems to be unique to each plant species, not varying by how much nutrients are in the water.
It seems to me if I provided additional nutrients in the substrate in a significant quantity the plant would grow fewer of these stem roots as it is getting more nutrients from the substrate. It also seems to me that the nutrients I need to provide would be a form of mg and ca.
Neither Ca nor Mg are macro nutrients. Macro nutrients are nitrogen, phosphorous, potassium and carbon. Those are the most needed by all plants.
Since I use clay based soils that are red I make the assumption that I am providing enough iron in my low tech environment.
Iron in clay is not bioavailable as it is. It needs bacteria to convert it to a bioavailable form. Chelated iron is immediately available to the plants, which is why we dose only that form of iron.
I make that assumption based on my roseafolia stays fairly red even in low light.
Alternanthia roseafolia is a plant that is naturally red, not one that takes unusual effort to make it become red. I'm not sure if it is ever just green.
I dont know maybe I am barking up the wrong tree here and am way off base which is why I am asking. I also figure this also points to the ideas about mineralizing soil. I also wonder lets say we sprinkle a substantial quantity of a nutrient mix, any nutrient really, under a high cec product like sts, cat litter, or turface placing it diectly on the base of the aquarium. We also precharge the high cec material with the same nutrient mix and place it over the bottom. Use a high clay content soil over the sts or whatever. Plant heavy from the get go. How much of our nutrients end up loose floating in the water column as opposed to staying in the sub/soil? Will the sub and cap act as a barrier and keep them out of the water column?
Whatever is in the substrate will soon be in the water too, but it may be that the concentration in the water won't be very high. I doubt that capping the substrate, or putting the nutrients under the substrate, will keep those nutrients out of the water at all.
My wife tells me I over think things lol. Reading this post I tend to agree with her but hey inquiring minds want to know!!
Questions like this, that I have quite often, make me wish I had taken some botany and organic chemistry courses in college. Of course any of us can do our studying of those subjects on our own too, but I learn a lot faster with a teacher involved. And, we are more likely to learn real facts and not get as many things confused that way.
 
#32 ·
General use

Dolomite is commonly used in a variety of products. A few of these are listed below:

  • antacids (neutralizes stomach acid)
  • base for face creams, baby powders, or toothpaste
  • calcium/magnesium nutritional supplements for animals and humans
  • ceramic glazes on china and other dinnerware (dolomite is used as source of magnesia and calcia)
  • fertilizers (dolomite added as soil nutrient)
  • glass (used for high refractive optical glass)
  • gypsum impressions from which dental plates are made (magnesium carbonate)
  • mortar and cement
  • plastics, rubbers, and adhesives
 
#34 ·
@Hoppy Thanks for the answer. That cleared up a lot of things for me. I appreciate it much!!
 
#35 ·
Day 2

Water is clear today. No sign of muddiness except for a very small amount silt on the bottom of the planter pond. The jar is still in three layers from darker at top, to white on bottom. I feel I could have poured in much more than .5 cups, and it would settle overnight.

The pH is somewhere over 7.6, because I don't have a proper test for higher pH. I'll go shopping.
The KH is the real surprise. It remains at 3-4 dKH. I did not know the KH for this planter pond before I threw in the dolomite. I expected it would go high with dolomite. Not the case.
I need a TDS kit. I've never looked for them before and assume they may not be at the LFS.
There were no fish in the little pond, so no report on that end.


 
#36 · (Edited)
#42 ·
Based on what I have read, and what I saw when it was used as a substrate, dolomite in any form, rocks, gravel, sand or powder, still dissolves extremely slowly. Remember, dolomite is a crystal form of material, so unless you grind it finer than the typical crystal size, if that is possible, it is still in the crystal form. I admit that I haven't tried it, so this is all based on theory, not experience.
 
#43 ·
I have no idea what the gravel i used in my tank is composed of, though it does come from the local quarry owned by the dolomite company... so... I'm assuming they named the company that for a reason, that and the region is known for large limestone/salt/dolomite/sandstone deposits, so it's entirely likely that there is a decent amount in the gravel (1/8" grain size or so, not quite mason sand, but close) and it's been in my tanks for 2-3 years... no cloudiness, decent plant growth, though i did wash the gravel of all it's "fines" before putting it in the tanks, and that is likely why there is no cloudiness. ph7.8-8.2/ gh 7ish/ kh 7ish depending on the water coming in to the tank

I do notice a gh/kh difference of about 2 each from the tank that has straight sand in in, with the gravel tank being higher, it also results in the ph being about 0.5 higher as well
 
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