High PH in RO water

[Alan]

Guys can anybody help me here. Firstly i have really cr*py tap water. It comes out of the tap with a PH of around 8.5 and has chloramine in it. So i have to first remove the chlorine and then filter through zeolites to absorb the ammonia and then through the RO membrane. Marco and myself spent many hours getting this right. My first membrane lasted about 2 months before the ammonia destroyed it, my second one has been in for about 4yrs and only gives me a TDS reading of 5, which is still fine after all that time. I do run through DI resin after the membrane to get the TDS to 0.
My ro water still has a PH of about 8.5 after the RO/DI process which is not a problem in itself with a marine system although i used to struggle with discus.
My question is this:With that amount of buffer[what ever it is] would it impede the dissolving of Calcium Chloride to add to the system, as i know the higher the alk and PH in salt water the less CA it can hold?

[Mekaeel]

what about the tropic marine triple buffer alan?no experience with it but i know it helps with stabalising PH.i do stand for correction here

[Alan]

No dont want to buffer RO, i use it to add calcium to the system and so dissolve a fair amount in the ro water to drip into the system over a period of time about 1 hour.

[Mekaeel]

did you manage to speak to marco again,maybe he managed to come up with an idea alan?

[Alan]

Idea for what?

[Mekaeel]

to see if he came up with what he can do to help sort out the ph prob from the RO

[viper357]

I know we are straying off topic here but why do you not want to buffer your RO? Many people do, Anthony Calfo has always strongly advocated the buffering of RO water before it is added to the aquarium.

[Mekaeel]

sorry off topic again.can tropic marine triple buffer sot out the ph in plain RO or in saltwater itself?

[Alan]

We really are getting side tracked here, i do buffer my top up water, what i need to know is will the high ph in the RO water impede its ability to hold an extremely high CA content used for raising the CA in my main system.

[Mekaeel]

soryy alan.went a bit off track there.lets see what our scientists have to say

[sunburst]

Originally Posted by Alan

We really are getting side tracked here, i do buffer my top up water, what i need to know is will the high ph in the RO water impede its ability to hold an extremely high CA content used for raising the CA in my main system.

Yes...the higher the ph the less soluble calcium (ie a shot of vinegar with your top allows you to supersaturate)....however i find it highly unlikely that ro water with 0 tds could possibly have such a high ph...something not right there

[Mekaeel]

Originally Posted by sunburst

something not right there

well we havent actually taken alans age into consideration there

[Alan]

Originally Posted by sunburst

Yes...the higher the ph the less soluble calcium (ie a shot of vinegar with your top allows you to supersaturate)....however i find it highly unlikely that ro water with 0 tds could possibly have such a high ph...something not right there

Has always been that way, really tried to get to the bottom of it when i bred Discus, but couldn't get the answers. I really dont know what they buffer the water with. But believe me when i say TDS 0 and PH 8.5 confuses me aswell and had Marco baffeled.

[phat]

Originally Posted by mekaeel

well we havent actually taken alans age into consideration there

hahaha very funny, i love the staff i reserve the right to insult them

Originally Posted by alan

We really are getting side tracked here, i do buffer my top up water, what i need to know is will the high ph in the RO water impede its ability to hold an extremely high CA content used for raising the CA in my main system.

why wouldn't it?

[Mekaeel]

i wasnt insulting,i respect my elders

[Alan]

Originally Posted by phat

why wouldn't it?

The higher the PH the higher the ALK, the higher the ALK the less CA it can hold, the reason snow storms happen in tanks.

[phat]

yes i know but why wouldn't it in RO, do you know of any reason that it wouldn't happen in the RO as opposed to SW

[phat]

i am assuming your are buffering your RO water with calcium?

[Alan]

RO normally has a slightly acidic PH of about 6.5 because of the lack of ALK, so would be able to saturate with CA. Now with the higher ALK levels can it still saturate with CA?

[Alan]

Originally Posted by phat

i am assuming your are buffering your RO water with calcium?

Phat you cant buffer with CA you can only add it to the water.
Buffer normally refers to alkalinity, which inturn buffers the Ph, hence it is termed a buffer.