Newbie questions

[gerald]

Not true; GH and KH are independent, in a chemical sense: GH hardness is due to +2 ions (mainly Ca+2 and Mg+2) whereas KH alkalinity is due to carbonate, bicarbonate, phosphate, and other ions that neutralize acids by binding with free H+ ions. With chemicals you can easily create hard water (high GH) with low pH and low KH, or create alkaline water (high KH) with zero GH. (Baking soda will do that). BUT in natural freshwater habitats the majority of GH and KH comes from limestone and similar rocks that dissolve to yield both GH and KH, so they're often fairly close in natural waters.

Another bit of misinformation that probably every aquarist has "read somewhere" is that water with high pH is "alkaline." Even the test kits often use the term "alkaline" when they really mean "basic". A weak solution of NaOH (sodium hydroxide = lye) will have a high pH, but low alkalinity (KH), since it takes just a little acid to neutralize it. KH is really a measure of pH stability (resistance to acid-induced pH change). So, you can have neutral water (pH 7.0) with very high KH, if it is well-buffered with right ions. Make sense?

 

[dw1305]

Hi all,

... Thanks for the explanation. I read somewhere that KH can never be higher than GH because KH is a part of GH?

It can be higher. The derivation of both terms is a bit strange, because <"it uses CaO as a starting place">.

The dGH is a measure of multivalent cations, usually just Ca++ and Mg++, and dKH is a measure of the carbonate content. If you add sodium bicarbonate (NaHCO3) you raise dKH, but not dGH, and if you add calcium chloride (CaCl2) you'e raised dGH, but not dKH.

cheers Darrel

 

[ButtNekkid]

Hi,

Thanks for the replies.That Krib link was really good.
Now, any ideas why my sphagnum moss didn´t make a dent in my tap water. After 24 hours the conductivity was the same, 120µS.
Could the CEC be "exhausted" from the moss? Should the water have some sort of movement?

I´d really like to try out that world famous "moss in a coconut" trick with my A. abacaxis

 

[gerald]

I dont think peat can lower conductivity. The principal behind CEC (cation exchange) is that it absorbs hardness ions (+2) by exchanging them for other ions (+1). It may even increase conductivity as it lowers hardness, since two Na+ ions have more conductivity than one Ca+2 ion.

 

[ButtNekkid]

I dont think peat can lower conductivity. The principal behind CEC (cation exchange) is that it absorbs hardness ions (+2) by exchanging them for other ions (+1). It may even increase conductivity as it lowers hardness, since two Na+ ions have more conductivity than one Ca+2 ion.

Hi,

My peat bucket lowers my tap water conductivity from 120 µS to 70-80 µS.
I´m a bit confused now. What happens when you put that moss in to a coconut as it lowers the ph in there?

 

[dw1305]

Hi all,

That Krib link was really good

I still refer to it, back then Ted and Mike were already giving out good advice.

I dont think peat can lower conductivity. The principal behind CEC (cation exchange) is that it absorbs hardness ions (+2) by exchanging them for other ions (+1). It may even increase conductivity as it lowers hardness, since two Na+ ions have more conductivity than one Ca+2 ion.

This is where you need @regani. I think you are right for ion exchange, but other processes cause the lowering of conductivity.

My peat bucket lowers my tap water conductivity from 120 µS to 70-80 µS.
I´m a bit confused now. What happens when you put that moss in to a coconut as it lowers the ph in there?

I think the answer is that, as well as ion exchange, you get chelation with sphagnum peat, and the bound ions no longer contribute to the conductivity. There is a discussion of this in <"700 liter Amazone"> .

Now, any ideas why my sphagnum moss didn´t make a dent in my tap water. After 24 hours the conductivity was the same, 120µS. Could the CEC be "exhausted" from the moss? Should the water have some sort of movement?

I'd try some water movement, but you may be right and you need some different peat.

cheers Darrel
https://apistogramma.com/forum/members/regani.9407/

 

[gerald]

Thanks - i thought peat was just a natural form of ion exchange; wasn't thinking about its chelation potential. Yes that would explain the conductivity drop.

 

[dw1305]

Hi all,

Thanks - i thought peat was just a natural form of ion exchange; wasn't thinking about its chelation potential. Yes that would explain the conductivity drop.

I've just found the other @regani chelation post I was after, it is in <"using peat granules.......">.

cheers Darrel

 

[ButtNekkid]

Hi,

How many Nannostomus marginatus would you put in 120 cm long tank? Half of the surface is covered in pistia and salvinia.
Apparently the new ones are wild. Any special considerations other than quarantine?

Stocking:

3-5 Otocinclus
10 Black neon tetras
1+2 A. cacatuoides harem
4 Cardinal tetras
5 Nannostomus marginatus

 

[ButtNekkid]

Hi,

Any opinions?

 

[gerald]

You didn't tell us the other tank dimensions, but assuming it's similar to a USA 40 or 50 gallon tank, you could probably safely house 40 or 50 small tetras and pencils along with the Apisto trio.

 

[ButtNekkid]

You didn't tell us the other tank dimensions, but assuming it's similar to a USA 40 or 50 gallon tank, you could probably safely house 40 or 50 small tetras and pencils along with the Apisto trio.

Hi,

Tank dimensions are 121 x 41 x 55. So I think it´s about 60G.
I´ll probably just add 5-6 more N. marginatus.

 

[gerald]

Might as well get a few more cardinals too, so you have 10-12 of each of the schooling species.

 

[ButtNekkid]

Hi,

Just wanted to share my tank with 100% cover. Inspired by Bart Hazes tanks.

 

[ButtNekkid]

Hi,

I have a 15 G with A. sp. abacaxis with eggs. Tank temperature is 29 °C. Is that too high?

 

[Mike Wise]

You'll probably get mostly males unless the lower the temperature 2 - 3°C.

 

[ButtNekkid]

You'll probably get mostly males unless the lower the temperature 2 - 3°C.

Thanks for the reply Mike.

What are lethal temperature levels for fry or grownups?

 

[Mike Wise]

I don't know if anyone has studied this but I'd worry if the temperature raised above 35°C/91°F (cooler than the temperatures we have had here the past week: 37 - 41°C!).

 

[ButtNekkid]

I don't know if anyone has studied this but I'd worry if the temperature raised above 35°C/91°F (cooler than the temperatures we have had here the past week: 37 - 41°C!).

And I thought I was dying here with 30 °C! Well... Finnish people like to complain about the weather A LOT...

 

[Ade205]

Finnish people like to complain about the weather A LOT...

I'm from the UK... reckon you Fins have met your match on this one!