水草情迷

Few days ago, I went to Wing Hing and got some K2SO4 to make my PMDD.
I try to mix mine close to Seachem one, which 1ml increase 1ppm for 40L tank.

I found that the chemical is not very soluble in tap water even I shake it hard!
Isn't the saturation point of K2SO4 far over that amount?

I'm an idiot in Chem..pls dont mind.

Sir, have u try hot water?
about 60-70oC

nope
would it alter the element?

I'll try, thanks!

Sir,I think this spread sheet can help u
http://www.wpbschoolhouse.btinternet.co ... bility.xls

Ah~ will u add KN03 too~?

It is safe I think.
ionic compound won't be decompose in that low temp.

Thz for your info!!
really helpful!!

I didnt add any KNO3....
My plant cant eat up self-contained nitrate..

why not try kcl is very soluble

其實KCL仲平0的添..不過我驚太多Cl唔係咁好...

另外, 係我用熱水開左K2SO4之後隔兩日, 有0的已經變反crystal form...點解會咁架?
唔通真係要開到好稀先保存到?
Seachem加左0的咩可以keep到40000mg/L 呢個ratio??

其實尼隻野水係幾難溶既...
用乙丙醇會好好多...不過落魚缸既...又唔用得
尼個情況可能只可以開稀d

40000mg/L = 40g/L
睇番張sheet,solubility 有110g/L at 20度,無理由唔溶

40000mg/L = 40g/L is the potessium level
to maintain this level we need about 90 grams of K2SO4...so very marginal..
Just query about how they keep this level...the smell of my mix and Seachem one is different, there must be some tricks~

K2SO4係無色無臭,有氣味,可能係用其他化合物同溶劑造
如果要增加溶解度,可以增加酸性,如加硫酸H2SO4
你可以開20000mg/L,每次落2mL for 40L tank

無一隻醇(alcohol)叫乙丙醇,除非係某D人既叫法,酒精溶解度一定差過水,呢個係極性問題

我用水喉水又可能有影響
唯有開稀0的~
Thz~

Ah...u are correct
I have misunderstand sth in this page
http://www.phasediagram.dk/mixeds/k2so4.htm

and 乙丙醇 is I-propanol (IPA)
a kind of organic solvent for cleaning

呢幅三角圖係咁睇
1.每隻角代表每一種野既100%,底係0%
2.有紅圈果條線叫臨界線,代表三種野-醇(alcohol)、水(H2O)、硫酸鉀(potassium sulfate,K2SO4)處於平行點(剛剛溶為一體),呢條線上每一處三樣野加埋都係100%
3.臨界線左面代表低/不溶區,右面先係溶解區
所以K2SO4根本唔溶係醇

係低/不溶區

Yes, u are right~
I have misunderstand the diagram ~ really sorry for that~
thanks for correction