Aquatic Plant Forum banner

Something to harden water?

8290 Views 17 Replies 11 Participants Last post by  Diana K
I'm just setting up my NPT and I don't want my soil to soften my water even more. I've checked out my local pet stores and none actually had crushed oyster shells to harden my water. Is there any other things I can use to harden the water? I've heard cuttlebones are able to, but how much would I put in the soil?
1 - 18 of 18 Posts
You can get crushed oyster shells in the bird section of a pet store. They sell them for birds to chew on. They're pretty cheap. Crushed coral would work too if they have it. They'll probably only carry it if they sell salt water aquarium supplies though.
might want to check local feed stores for oyster shells.
me has poured some "garden lime" into the soil to neutralize its ph.
dunno what it's called at your place.
regards
Why do you want to harden your water?

Many of us have the opposite wish.

Bill
I'm just setting up my NPT and I don't want my soil to soften my water even more. QUOTE]

I advise that people increase their water hardness if they have excessively softwater with a GH less than 4 AND they are getting poor plant growth.

Excessively softwater does not contain enough of the major nutrients calcium, magnesium, etc to get good plant growth. Indeed, one hardwater plant died in water without calcium (even though it had calcium in the substrate). Most aquarium plants do much better in hardwater than softwater. I documented this in my book with scientific data and my own experiment (pp. 112 to 122).

Tapwater in the Raleigh NC area close to me is very soft. Hobbyists can't get good plant growth without increasing water hardness.

Most soils will increase water hardness, not decrease it (my book, p 131). I would measure your tank's water hardness. Only if the GH is 1-3 and plants aren't growing, would I worry about increasing water hardness.
Hectic didn't state what the KH and GH of her water was. I assumed that she was more concerned about the KH, which doesn't have much effect on plant growth.

If one wants to raise the GH, there are products that add calcium, magesium, and other minerals without affecting the KH. Two that come to mind are Barr's GH Booster and Seachem's Equilibrium. Using products like those provides more precise control over GH levels than does dissolving oyster shells.

Bill
If one wants to raise the GH, there are products that add calcium, magesium, and other minerals without affecting the KH. Two that come to mind are Barr's GH Booster and Seachem's Equilibrium. Using products like those provides more precise control over GH levels than does dissolving oyster shells.

Bill
SeaChem's Equilibrium has too many sulfates. All the ingredients it contains are sulfate salts. In an organic soil like potting soil, bacteria will convert these sulfates to toxic H2S (my book, p 67). H2S will definitely poison roots and inhibit plant growth. Equilibrium works fine in High-tech tanks, because they usually don't have an organic substrate.

Also, at the top of this forum is a stickie 'Useful Procedure for NPTs' with a good procedure to increase water hardness. Basically, you're adding calcium in the form of calcium chloride, which quickly dissolves, won't add sulfates, and won't increase pH. However, you still have to add all the other hardwater nutrients (magnesium, potassium, etc). So, its a bit complicated.

If Tom Barr's GH Booster contains calcium chloride instead of calcium sulfate, then I'd go with it. (And please tell us all where to get it.)

I'm ever so glad that I have hardwater!
Hi,

I've read your book several times. Putting into practice the things I've learned from it, I now consider myself a more or less successful aquatic gardener, most of the time, knock on wood :)

I usually use soft, acid water for my NPT's. I collect it from a small stream that flows through a swamp. The GH is around 1 or 2, so I augment it with Equilibrium. I've done this in about 10 tanks over the last several years.

I have never noticed the odor of H2S gas. (I know what it is, since I used to make it with my home chemistry set, using wax and sulphur, as I recall, until my parents confiscated the sulphur.)

My plants grow quite well, including heavy root feeders like vals, crypts, and swords. I wonder if there might not be some variable that, with the sulfates, causes the problems that you've identified, such variable not being present in all aquariums?

BTW, Barr's GH Booster also uses sulfate salts.

Thanks for your response.

Bill
See less See more
Seachems Equilibrium or you can ask Orlando at www.greenleafaquariums.com if he will mix you up a custom blend of just calcium and magnesium sulphate should you not want iron and/or potassium.
Seachems Equilibrium or you can ask Orlando at www.greenleafaquariums.com if he will mix you up a custom blend of just calcium and magnesium sulphate should you not want iron and/or potassium.
I would ask him to make the regular mix, but only with calcium chloride instead of calcium sulfate. Calcium is the main ingredient for increasing water hardness. If the chemist can provide it as a chloride salt instead of sulfate salt, it should eliminate potential problems in NPTs. A little sulfate is fine, if not helpful, but products that contain nothing but sulfate salts could be a problem.

One European hobbyist did a comparative study seeing effect of calcium chloride v. calcium sulfate salts on his plants. Although this was not a scientific study, he reported that he got noticeably better plant growth with the calcium chloride. It does not surprise me.

These concentrated sulfate products are fine for High-tech tanks and NPTs with a mineral soil. For NPTs with an organic soil, they may be better than nothing, but they're not ideal.

I don't know what the objection is to using more chloride salts in water hardeners. I've discussed this with SeaChem, and they say they don't like to add chloride. Well, there's nothing wrong with chloride (as in sodium chloride), especially in the moderate amount required to bring up water hardness. Plants take up large amounts of chloride into their tissues, so chloride will be removed via plant pruning.

Balance is always best- a water hardener with a mixture of chlorides and sulfates is much better for NPTs than one with pure sulfates. Until someone can provide a water hardener with less sulfates, I'd not turn my back entirely on oyster grit, crushed sea shells, and dolomite lime. The calcium is harmless calcium carbonate, plus these natural products contain a little magnesium and some of the other hardwater nutrients.
See less See more
Balance is always best- a water hardener with a mixture of chlorides and sulfates is much better for NPTs than one with pure sulfates. Until someone can provide a water hardener with less sulfates, I'd not turn my back entirely on oyster grit, crushed sea shells, and dolomite lime. The calcium is harmless calcium carbonate, plus these natural products contain a little magnesium and some of the other hardwater nutrients.
Diana,

I'm new to this forum and first I'd like to thank you profusely for the time taken here helping others. I've read your excellent book a few times now, and currently I'm assembling my first 100 liter NPT. I'm excited, as a biology student, to observe its ecological succession after I add my first batch of plants :)

I have a technical question though:

My tapwater is extremely soft here in Brazil, not registering any hardness at all on aquarium test kits. I have access to lab grade chemicals, including chlorides of Mg, Ca and K. I was thinking of making 1M solutions of these salts and calculating the amount necessary to raise my hardness to something closer to 7dKH. Is this feasible, do you think, using chlorides only? If so, what's the molar ratio of Ca:Mg:K that you think appropriate? Sorry if this has been asked before.

Thanks in advance!
*** Until someone can provide a water hardener with less sulfates, I'd not turn my back entirely on oyster grit, crushed sea shells, and dolomite lime. The calcium is harmless calcium carbonate, plus these natural products contain a little magnesium and some of the other hardwater nutrients.
This thread is of great interest to me because I have five tanks, three doing moderately well (but with some problems) and two still to set up and I want them all to be NPT's. I have medium hard tap water but with huge variation in its GH and KH and chemistry because of local agro-industry levels of ferts (I guess) in the aquifer. Hence I got myself an RO water filter and have been using Seachem's Equilibrium until now.

Now Ive joined this forum I'll post separately about transitioning the 5 tanks we have to NPT's but for now I'm keen to get my RO water right for planted low-tech tanks in general without cutting in tap water if I can avoid it (because it fluctuates so much).

Anyway, re the above quote from Diana: http://dennerle.com/en/products/aqu...ning/osmosis-water-treatment/osmose-remineral

. . . might be interesting? It seems to use both chlorides and sulphates and it gives Anion/Cation percentages with the sulphates at 32% which I assume is a step in the right direction compared to Seachem using 100% sulphates

A heartfelt thank you Diana for all your efforts over many years.
Julian
See less See more
I have not seen activity by dwalstad for quite a while at this site. Note that this thread is over 5 years old.

I wonder if the product linked has too much sodium? I do not know how much is 'too much'.

I also wonder about their claim of
...Select organic substances activate the filter bacteria...
WHICH filter bacteria? The ones aquarium keepers are most concerned with (the nitrogen cycle organisms) do not utilize organic matter, but get their carbon from carbonates, and their other minerals from simple molecules, not organic ones. This can be proven by doing a complete fishless cycle in a bucket of water with just filter media, a few minerals and ammonia.
Heterotrophic bacteria are the ones that utilize organic materials, perhaps this product is pushing these?

I would interpret their percentages a little bit differently.
Look at the pie charts.
The 32% sulfates is as a % of all the anions (negative charged molecules).
I do not see it as the source of all the ingredients is 32% sulfate based (as in potassium sulfate etc.) the way you are saying Seachem Equilibrium is 100% sulfate versions of each mineral. Looking at the Seachem site, ingredients for Equilibrium it seems sulfate is about 70% of the jar, and all the other minerals (K, Ca, Mg, Fe, Mg) put together make up about 30%. (Ferts are based on % by weight in the US). This product does not contain carbonates in any form, so to compare it with a product that does contain carbonates we would have to blend it with some source of carbonates (sodium bicarbonate???) until it produces the same rate of change to both the GH and KH as the product you linked.

I think looking at the actual ingredients would be important.
See less See more
Best chemicals to harden water:

MgCO3 - raises Mg without raising Ca. You can really dial the Mg then. It raises KH too because of the CO3 but not a lot. Must blend in a food blender to suspend the fine particles even more. Tank water gets cloudy for 30 mintutes then clears up completely. Does not add Suphur (SO4) which is a downside to using Epsom Salt (MgSO4) because the S accumulates and causes stunted growth.


CaCO3 - raises Ca without raising Mg. Will raise KH but not too much. Does not add Suphur (SO4) which is a downside to using CaSO4 because the S accumulates and causes stunted growth.


Dolomite - raises both Ca and Mg but it does that very gradually and the plants do exhibit better growth with such slow release.


Forget commercial GH boosters. Adding something that raises both Ca and Mg is not a good idea because normally you want to adjust the Ca:Mg ratio to be close to 4:1. Which is a big deal, very big deal, no matter how many people dispute that on the internet.
See less See more
Hi Diana K - thanks for the reply. I was aware that the thread was very old, but since I've spent the last several weeks researching this exact issue (and someone else resurrected the thread quite recently), the answers still aren't obvious . . . mostly of course because these companies aren't very quick to disclose their precise ingredients. Dennerle are a European company that are certainly well known and I think pretty highly respected though of course their focus is the more orthodox hi-tech aquarium set ups.

Your right Equilibrium has no effect on the KH - they want you to buy their "Alkaline Buffer" product to change that.

Also this is the first time I've read about the possible clash between Equilibrium's sulphates and soil-based substrates. From such an authority as DW I take that as meaning I need to find a different way forward if one's available and since so much of what I'm about to do is kinda radical, (with the orthodox being hi-tech) I'd like at least one pretty stable factor in the mix i.e. the water I put in.

Alternatively is there a simple formula for re-mineralising RO water specific to the soil-based substrate planted tank I've not stumbled across as yet?

Thanks
See less See more
Best chemicals to harden water:

MgCO3 - raises Mg without raising Ca. You can really dial the Mg then. It raises KH too because of the CO3 but not a lot. Must blend in a food blender to suspend the fine particles even more. Tank water gets cloudy for 30 mintutes then clears up completely. Does not add Suphur (SO4) which is a downside to using Epsom Salt (MgSO4) because the S accumulates and causes stunted growth.

CaCO3 - raises Ca without raising Mg. Will raise KH but not too much. Does not add Suphur (SO4) which is a downside to using CaSO4 because the S accumulates and causes stunted growth.

Dolomite - raises both Ca and Mg but it does that very gradually and the plants do exhibit better growth with such slow release.

Forget commercial GH boosters. Adding something that raises both Ca and Mg is not a good idea because normally you want to adjust the Ca:Mg ratio to be close to 4:1. Which is a big deal, very big deal, no matter how many people dispute that on the internet.
Hi Niko thanks for the reply.

The Dennerle product I linked to has Calcium 45,5 % Magnesium 9,5 % which is pretty close to 4:1

Not that I'm advocating or defending it - I only learned it existed an hour or so ago!

So I've got a 120 litre barrel or RO water, exactly what do I add to it so I have replaced everything that's lacking for plants and fish to be healthy? I don't mind mixing up a batch of raw ingredients, I just want to get it right and understand enough about what I'm doing so I can make changes depending on the water parameters I want: For example I might want one mix for an NPT 50% water change (in the early days) but another for my existing inert gravel substrate planted tank and theoretically another for a soft water apistogramma breeding tank thats also planted.

The Dennerle product suggests its possible to dial such things in pretty accurately, which I like, but I'm always keen to avoid the commercial option especially when its expensive and even more especially when its assuming I'm using ADA Amazonia . . .
See less See more
What is the goal for the GH? This value should suit the fish. Research the fish.
Hard water fish want a higher GH than soft water fish.
Plants will grow under a much wider range of conditions. There are a few specialty plants that will demand specific conditions, but these are not so common in planted tanks.

Here is how I do it:
Make the GH suit the fish. Using whichever materials you want, the target of 4 parts Ca: 1 part Mg is good.
Make the KH match the GH. This does not have to be perfect. KH acts as a buffer to stabilize the pH. In general soft water (low GH) is usually low in carbonates, and hard water (high GH) has more carbonates, which is why I start by making the GH and KH roughly equal. But you can alter the ratio if needed, to maintain a particular pH, if you want to. I never worry too much about pH, if the mineral levels are right.
You can also use peat moss or other organic material to add the organic acids to the water that some fish like.

I like the idea of using each material separately, so you can adjust the exact amount based on the other things going on in the aquarium or the water supply.
See less See more
1 - 18 of 18 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top