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Do I need GH/CH?

Simmo

Member
Joined
11 Dec 2020
Messages
311
Location
Scotland
Hi
The water here is super soft with 0-1 degree of GH and zero Carbonate hardness. I have a planted tank with neons and will be stocking a few more tetras and a pair of apistos.
i have read that you need some gh/ch for healthy plants and fish so I did start to dose with equilibrium but its a pain when you do a lot of water changes and is it necessary?
Thanks
 
Yes, it is necessary for a stabile environmnt in the aquarium. Zero Carbonate hardness is very dangerous for a sudden decrease of the pH-value. Plants also need calcium and magnesium.
 
Hi
The water here is super soft with 0-1 degree of GH and zero Carbonate hardness. I have a planted tank with neons and will be stocking a few more tetras and a pair of apistos.
i have read that you need some gh/ch for healthy plants and fish so I did start to dose with equilibrium but its a pain when you do a lot of water changes and is it necessary?
Thanks
Hello,
By the way, Carbonate Hardness is referred to as KH, not CH (which can cause confusion).
In any case, as mentioned above, Calcium and Magnesium , which comprise your GH reading, are plant micronutrients, which means you don't need a lot, but some should be present for best performance. You can add a bit of Epsom's Salt for Magnesium or you can find generic products called GH Booster which add both Calcium and Magnesium salts. You only need enough to raise the GH a couple of units, say 2-4. There are other more well known products from bigger companies that do the same thing. Equilibrium from Seachem is a popular product.

If you are keeping the typical Amazonian fish found in pet shops, such as tetras and so forth, then KH is much less important, however, pH probes don't work well with very low KH so you can add any product with the term "ph buffer" or "Alkaline buffer" enough to raise the KH to about 3-4.

I'll have to disagree with the statement above regarding the so-called danger of sudden pH decrease. Tanks using injected CO2 experience sudden pH decreases every day without any ill effects to fish or plants. In our experience, pH stability is highly overrated.

Cheers,
 
Hi all,
The water here is super soft with 0-1 degree of GH and zero Carbonate hardness. I have a planted tank with neons and will be stocking a few more tetras and a pair of apistos.
i have read that you need some gh/ch for healthy plants and fish so I did start to dose with equilibrium but its a pain when you do a lot of water changes and is it necessary?
You can make your own bespoke mix with potassium bicarbonate (KHCO3), calcium chloride (CaCl) and Epsom Salts (MgSO4.7H2O). These are all easily available via ebay, because they have food or medicinal uses. The other option is to add some <"oyster shell chick grit"> (CaCO3).

Naturally you tend to get similar amounts of dGH and dKH, because they both originate from <"dissolved limestone (CaCO3)">. The derivation of the various units is in Larry Frank's article at <"the Krib">.

A lot of Apistogramma keepers use water with very low dKH/dGH values, in fact it is a prerequisite for long term maintenance of "black water" fish (like Parosphromenus) and the <"Rio Negro basin"> Apistogramma species. Have a look at <"All the leaves are brown">, written by Colin Dunlop, it is a very useful reference for Apistogramma keepers.

An essential read is <"TomC's web site">, he has been frequent visitor to S. America and has taken <"pH and conductivity readings"> at the sites he has visited.

The same applies to plants as to the fish, some of them are adapted to very acidic conditions and don't really thrive away from them. @Roland has grown a lot of them and can tell you about the <"water parameters and plants he uses">, the water parameters are similar to those recommended by @JamesC at <"James' Planted Tank">.

Because <"pH isn't a very useful measurement"> in very soft water, I use <"a conductivity datum">, where I add enough hardness and nutrients for some plant growth, but still maintain soft water.
I'll have to disagree with the statement above regarding the so-called danger of sudden pH decrease. Tanks using injected CO2 experience sudden pH decreases every day without any ill effects to fish or plants. In our experience, pH stability is highly overrated.
I should have said I agree with Clive. There is more explanation in the linked threads, but once you know that you can raise and lower the pH values by one unit (and pH is a log10 scale) using CO2, without damaging your fish, you know that there is more to it than just pH.

cheers Darrel
 
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You can make your own bespoke mix with potassium bicarbonate (KHCO3), calcium chloride (CaCl) and Epsom Salts (MgSO4.7H2O). These are all easily available via ebay, because they have food or medicinal uses. The other option is to add some <"oyster shell chick grit"> (CaCO3).
Hey Darrel,

I'm still using Seachem Equilibrium and Alkaline Buffer but always thinking I should swap to DIY (as you recommend it every time I read or ask about WC). Do you have a mixing ratio for the above and does it just raise GH/KH in alignment?

At the moment I'm quite anal about hitting a 6/6 mix (API test kits) using tapwater (starts 2/0) but fancy making things easier on myself and just going TDS method. Can this be done with tap water? I was using RO but too much of a pain in the butt and seems wasteful, plus the extra cost of powders. It was an attempted to cut out silicates and stop diatoms but didn't work.

Maybe once I get this part onto DIY I can look at doing the same with ferts.
 
Hi all,
Do you have a mixing ratio for the above and does it just raise GH/KH in alignment?
If you use "Shell Chick Grit" you get a 1 : 1 ratio of dGH (Ca) / dKH (CO3). If you use the salts you can have any <"arrangement of dGH and dKH you like">.
You would still need to add a very minimal amount of calcium (Ca) and a minimal amount of (Mg) for plant growth.
and just going TDS method. Can this be done with tap water?
Yes, you just get a datum range where you are happy with plant growth. <"I use 80 - 140 micro S.">, there isn't anything magical about those values, it is just that I live in a limestone area and even the rain-water has some dGH / dKH.

Your tap water will have a low initial conductivity (TDS value), but a high pH (pH ~8). The pH is from <"added sodium hydroxide (NaOH)">, which is partially why I'm not that keen on just using pH.

cheers Darrel
 
Thank you all for taking the time to reply, it's much appreciated. I've gathered a bit of data from my water provider and my tank as below.

Water provider (2019 annual data report, mean values)
Calcium 8.61 mg ca/l
Magnesium 1.28 mg/MG/l
26.76 mg/l of CaC03
pH 7.9

Off topic but also
Ammonium (total) 0.31
Nitrate 1.66
Nitrite 0.03

My Tank (using a 'number of drops before it changes colour' test tube kit so not wildly accurate)

KH 1-2
GH 2-3 (nearer 2 probably)
So 2 for both overall probably...

I think pH is between 6 and 7 in the tank based on test tube and cheapo Ebay meter tests but accept this could be wrong due to low hardness. If it is averaging 7.9 out of the tap and then has tannins etc added this sounds about right? Ideally it would be better a wee bit lower but seems broadly suitable for the fish I am/want to keep. Thanks for the links Darrel!, I enjoyed the leaf article and James tank page, I'd seen Tom's before. I have considerable tannins in the tank, it looks like tea a day after a water change, probably as I have large bits of local Quercus robur in there that is heavily weathered (read slowly rotting) plus I added some dead beech (Fagus sylvatica) leaves and also foraged some old, woody and dead heather (Caluna vulgaris) stems you can see on the right hand bottom corner - maybe these are acidic?. I might be on the right track here?


I really want to keep dosing with anything to a minimum as I am away a lot with work and the tank gets only minimal care during that time. Gosh, where does this leave me? I guess I am thinking hardness of around 2 might just be enough for the plants I have and means I don't have to dose anything? Maybe add a bag of oyster shell as a low maintenance way to add a little?

Plants I will have to look into - I have common species currently (Amazon swords, crypts, java fern, vallis, frogbit and a little Anubias nana) but can look to introduce more species from James list over time if they might be better adapted to the low hardness.

FYI this was the tank yesterday after a 50% water change, (poor Anubias on the right got frozen in the post and has since been removed).

View.JPG


Cheers
Dave
 
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I suspect your plants and fish will do great with exactly what comes out of your tap - the parameters are almost perfect for soft water fish - I certainly wish I had that coming out of my taps!! Assuming you are dosing some Magnesium as part of your fert regime, that will bring the GH up a little further, so I would say you might only need to add a little more Calcium if you choose to have any shrimp.
 
Hi all,
Water provider (2019 annual data report, mean values)
Calcium 8.61 mg ca/l
Magnesium 1.28 mg/MG/l
26.76 mg/l of CaC03
pH 7.9
Perfect, you don't need to add any more calcium (Ca) for plant growth.

In terms of dGH / dKH (from <"the Krib"> thread linked in earlier in the thread.)
1dGH = 17.86 ppm CaCO3 and 7.143 ppm Ca2+....1dKH = 17.86 mg/liter CaCO3.... 1dKH = 21.8 ppm HCO3
The high pH value is back to the NaOH addition, does the report give a conductivity value? I'm going to guess in 50 - 100 microS range.
Off topic but also
Ammonium (total) 0.31
Nitrate 1.66
Nitrite 0.03
Perfect, it is pretty much RO straight out of the tap, I would use a water conditioner like Prime because of the ammonia reading.
I certainly wish I had that coming out of my taps!!
Same for a lot of us.

cheers Darrel
 
Hi all,

Perfect, you don't need to add any more calcium (Ca) for plant growth.
That's good news, thanks.
In terms of dGH / dKH (from <"the Krib"> thread linked in earlier in the thread.)

The high pH value is back to the NaOH addition, does the report give a conductivity value? I'm going to guess in 50 - 100 microS range.

Thanks I did look at the thread - it completely lost me!

Good guess Darrel, yes it does, 74.96 microS
Perfect, it is pretty much RO straight out of the tap, I would use a water conditioner like Prime because of the ammonia reading.

That's great, yes I use conditioner - can't get my head around Prime as can't calculate dosing with any accuracy for 50-100litres (my problem I know it's used by loads of folk!) so use a Fluval product - more expensive but easier for me.
Same for a lot of us.
There's plenty of room in rural Scotland and you'd be welcome :)
cheers Darrel
 
I suspect your plants and fish will do great with exactly what comes out of your tap - the parameters are almost perfect for soft water fish - I certainly wish I had that coming out of my taps!! Assuming you are dosing some Magnesium as part of your fert regime, that will bring the GH up a little further, so I would say you might only need to add a little more Calcium if you choose to have any shrimp.
Thanks Wooki, the downside is there's not a decent LFS within 100 miles!
Yes I am dosing TNC complete at a roughly estimated EI of 5ml/day (as opposed to 20ml a week) for a 200 litre tank. This has a stated 0.8% Magnesium. Sound OK?
Cheers
Dave
 
Thanks Wooki, the downside is there's not a decent LFS within 100 miles!
Yes I am dosing TNC complete at a roughly estimated EI of 5ml/day (as opposed to 20ml a week) for a 200 litre tank. This has a stated 0.8% Magnesium. Sound OK?
Cheers
Dave

I'm sure that's probably fine for a low tech given the plants you have. As I say, only if you have shrimp you might want to review, and even then you can always just try dietary supplementation with higher calcium foods like mulberry and nettle leaves etc.
 
That's great, yes I use conditioner - can't get my head around Prime as can't calculate dosing with any accuracy for 50-100litres (my problem I know it's used by loads of folk!) so use a Fluval product - more expensive but easier for me.

Prime dosing is 5ml per 200 litres, so 1.25ml for 50 litres or 2.5ml for 100 litres.

A small 1ml syringe helps no end . . .

Amazon product ASIN B00SFS3ZHO
 
I'm sure that's probably fine for a low tech given the plants you have. As I say, only if you have shrimp you might want to review, and even then you can always just try dietary supplementation with higher calcium foods like mulberry and nettle leaves etc.
Thanks, I quite fancy an Amano or two so will bear that in mind
 
Yes, it is necessary for a stabile environmnt in the aquarium. Zero Carbonate hardness is very dangerous for a sudden decrease of the pH-value. Plants also need calcium and magnesium.
Apologies, my first post was inaccurate and I obtained better data, so there is some GH/KH, albeit fairly low.
 
I'll have to disagree with the statement above regarding the so-called danger of sudden pH decrease. Tanks using injected CO2 experience sudden pH decreases every day without any ill effects to fish or plants. In our experience, pH stability is highly overrated.
Agreed- see
 
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