PH very low, why?

[marinemanmercer]

Hi all,
Im only after installing a new calcium reactor to my reef system.I also changed my ph probe as my old one was 2 yrs old .The reading i got on my old one was a swing from 8.05 tp 8.2 but now with the new probe im getting a reading of 7.7.I attached the new probe when my light were just about to come on.I also done a ph test and its reading also aprox 7.7.Im wondering was my reading always very low or just when i swapped reactors as i never had changed my ph probe for so long.Whats my best bet to stabilze my ph again I forgot to add im also using a kalk stirrer which comes on 2 hrs before my lights go off and stays on for aprox 10hrs.I have also been using seachems magnesium buffer as my mag levels are low,not sure if that would mess with my ph levels.Any help would be great.

Thanks Trevor

[reverendmaynard]

Did you calibrate the meter with the new probe?

Either the meter is off (I don't trust any PH test kit), or you're pumping too much co2 into the reactor. Maybe the kalk in the stirrer is spent?

Magnesium should have no affect on the PH.

[marinemanmercer]

Thanks for the reply.To be honest im waiting on 7.00 calibration fluid so only got the 4.00 done so maybe thats why.Im also getting a ph controller for my 600s reactor so i will know exactly what co2 to put in as at the moment its a guessing game.I changed the kalk in the stirrer just last week.

Trevor

[lpkirby]

if you are calb correctly, then you need to slow your bubble count down.

[marinemanmercer]

Im going to order a ph controller tonight, hopefully that will sort it ok

[theop]

Check your alkalinity.

[marinemanmercer]

Just done a alkalinity test and the reading from my tank is 12.2dKH instead of 8dKH

[reverendmaynard]

You'll probably find that your calc is quite high as well. Classic signs of too much co2 in the reactor.

[marinemanmercer]

I have turned down my co2 going into the reactor to see if that helps.Its going in at aprox 1 bubble per sec instead of 3.My cal reading from my tank is at 400ppm which i was hoping to raise that to 460ppm.

Trevor

[reverendmaynard]

Hmmm? Is that 400ppm higher than it had been previously? You're not using any kind of buffers or anything are you? Using RO water?

[marinemanmercer]

Yes its went from 360 to 400ppm as i changed my calcium reactor from the deltec 509 to the bigger 600s model last week.The only buffer im using is seachems magnesium buffer.Yes i also use RO water ok.

Thanks Trevor

[reverendmaynard]

Aah, that makes sense now. Both Calcium Reactors and Kalkwasser are balanced supplements, meaning they have calcium and alk in the same ratio that corals use them. When you try to raise your calcium, you also raise your alk. You should use a calcium additive (like just the calcium part of a 2-part, or calcium chloride) to get the one-time raise in your calcium to where you want it, then use your current methods to maintain.

[marinemanmercer]

Would any calcium buffer do or do you know of one thats good.Many thanks for your help reverendmaynard.

[reverendmaynard]

I'm not really sure. I use Randy's 2-part recipe myself. Snow melt made from calcium chloride.

Here's a link to a reef chemistry calculator. You can use any of the products listed under the calcium section (except limewater), and the calculator will help you figure out how much to add.


http://reef.diesyst.com/

HTH.

[marinemanmercer]

ok thanks for that

[reverendmaynard]

No problem.

I just noticed there is a link to a Calcium Rector Setup Help page to the right of the graph on the calculator page. Might help you dial it in.

[marinemanmercer]

ok many thanks