Kalk And Ro

Joined
10 Mar 2008
Posts
800
Reaction score
5
Location
Pretoria
OK i was reading a thread now now about topping up with RO water and i think it was jacquesb that said one must add kalk to the RO?

firstly what is kalk?
secondly ive topped up with about 75 litres of R.O already and P.H is still 8.4
lastly is kalk expensive? cause this hobby is too much$$$ already
 

jacquesb

Retired Moderator
Joined
29 May 2007
Posts
17,868
Reaction score
71
Location
Cape Town
Hello Geoffrey -

Here goes:
Kalkwasser =
Calcium hydroxide mixed with white spirit vinegar mixed with RO water....

Calcium Hydroxide = "Slaked Lime" or "Gebluste Kalk" - and this you can get from ANY decent chemist. It should be on the rack with chemicals in powder format.
You should not pay more than +-R5 to R6 per 50 grams box of Slaked Lime....

The ratio that the mixture is mixed to, that I use, is:
+-15 grams of Calcium hydroxide, mixed to +-200-250ml of white spirits vinegar, mixed to +-2 litres of water.

I then dose +-50ml of this mixture at least 3 to 4 times per week to the return section of my sump....

You can add this directly to your RO container as well, if you have an auto-topup....

Hope you understand.
 
Joined
13 Feb 2008
Posts
1,434
Reaction score
74
Location
Cape Town
After about 15-20mi a white layer forms at the bottom of the container... Do i mix it when i want to add to my tank or pour only the clear in?
 
Joined
18 Oct 2007
Posts
6,377
Reaction score
70
Location
capetown,durbanville
OK i was reading a thread now now about topping up with RO water and i think it was jacquesb that said one must add kalk to the RO?

firstly what is kalk?
secondly ive topped up with about 75 litres of R.O already and P.H is still 8.4
lastly is kalk expensive? cause this hobby is too much$$$ already
buy it from your chemist ,very cheap, kalk, calcium supplement, ph is fine
 
Joined
18 Oct 2007
Posts
6,377
Reaction score
70
Location
capetown,durbanville
After about 15-20mi a white layer forms at the bottom of the container... Do i mix it when i want to add to my tank or pour only the clear in?
this means that your solution is saturated, pour only the clear liquid otherwise you will cause a calcium storm in your water , this is where the calcium is pulled from your water resulting in a ph drop (ps kalkwasser ph approx 12)
 

viper357

Admin
Joined
4 May 2007
Posts
29,894
Reaction score
1,412
Don't buy kalkwasser from a LFS, go to a chemist and buy Slaked Lime. It's dirt cheap.
 
Joined
8 May 2007
Posts
2,420
Reaction score
25
Location
Durban
OK i was reading a thread now now about topping up with RO water and one must add kalk to the RO?
The easiest way. You must automate

firstly what is kalk?
CaOH Calcium Hydroxide
secondly ive topped up with about 75 litres of R.O already and P.H is still 8.4
Thats a lot of RO. Are you dosing with buffer
lastly is kalk expensive? cause this hobby is too much$$$ already
No.......Copy Jac.
 
Joined
10 Mar 2008
Posts
800
Reaction score
5
Location
Pretoria
i used ph propper 8.2 a little while back and that seems to have helped. but its expensive and i dont know how long it will last. my Kh is 12 which is also good right?

do i only need to add kalkwasser once my tank has corals in it? cause i have a very low bio load at the moment and no corals so i doubt i'll need hey?

just worried about my P.h fluctuating too much by topping up with R.O water
 

martin

Reef Adict
Joined
8 Aug 2007
Posts
397
Reaction score
4
Location
Faerie Glen Pretoria
IMO With your KH @ 12 I suggest you check your Ca and Mg because I bet they will be out of sinc.
Better would be
KH8-9
Ca 380-430
MG 1150-1400
 
Joined
15 May 2007
Posts
2,899
Reaction score
118
Location
Bloemfontein
OK i was reading a thread now now about topping up with RO water and i think it was jacquesb that said one must add kalk to the RO?

firstly what is kalk?
secondly ive topped up with about 75 litres of R.O already and P.H is still 8.4
lastly is kalk expensive? cause this hobby is too much$$$ already
Good info so far... but just to add:

  • You don't NEED to use kalk with the RO, especially if the tank is still young, and you don't have many corals.
  • Your pH of 8.4 is perfect - why do you want to change it? Keep in mind that adding kalk will INCREASE the pH, and you don't want it to increase above 8.5 without good reason.
  • I would suggest that you check your alkalinity and calcium level before making the decision to add kalk.
Adding kalk is a very good thing for the long-term stability of your tank, BUT it does contain some element of risk (can kill everything in your tank!) if you're not careful and knowledgeable - so first determine if you need to add it at this point in time.

Hennie
 
Joined
28 Dec 2007
Posts
12,781
Reaction score
31
Location
JHB
ro water won't bring ph up or down
Will bring it down as ph of RO (or at least mine is 7), so it would decrease your 8.4 if you did huge water changes with RO only.

But as top up doesn't effect to too much
 
Joined
10 Sep 2007
Posts
9,395
Reaction score
26
Location
Centurion
yip, i ment with top up.
and with wc it won't do anything if you use the right salt.
Am i right war?
 
Joined
10 Mar 2008
Posts
800
Reaction score
5
Location
Pretoria
ok just an update on this thread. i have now got 2 little monty frags and a ricordea. i want to bring my calcium levels up a bit as i've noticed a slowing in my coraline algae growth.

my Alk is at 9
P.H 8.5

Gonna go to the chemist and buy some slaked lime (calcium hydroxide) gonna add 3 tsp of this to my R.O top up and see if it makes a difference.

350l 4ft tank...
 

Similar threads


Top