Effluent Alk = 0 ???

[lewismw]

I am having trouble getting my new Geo 612 working correctly i think.
I have the effluent Ph set at 6.5 for over a day now and the Alk reading is 0.
I get no color change on the Lamotte test at all. I have cranked up the C02 input to about 120+ BPM.
I understand i am supposed to be getting about 2-3 times the normal level for my tank.

Does anyone have any information on why Alk of the effluent is 0???

[RokleM]

<a href=showthread.php?s=&postid=12888602#post12888602 target=_blank>Originally posted</a> by lewismw
I am having trouble getting my new Geo 612 working correctly i think.
I have the effluent Ph set at 6.5 for over a day now and the Alk reading is 0.
I get no color change on the Lamotte test at all. I have cranked up the C02 input to about 120+ BPM.
I understand i am supposed to be getting about 2-3 times the normal level for my tank.

Does anyone have any information on why Alk of the effluent is 0???

No color change at all, meaning you use a whole syringe without the color changing? That means your alk is higher than a whole syringe can register. If it was truly a 0 reading, two drops out of the syringe should change the color to pink (over reading).

Personally, I would go grab an Elos kit for this type of testing since it scales to higher numbers a bit better. If you want to use the LaMotte, I'd use 2.5 mL instead of 5, doubling the outcome of your final number. i.e. if you use 140 of the liquid, your final outcome is actually 280.

I wouldn't be surprised if you use almost a whole syringe at 2x multiplier. My 618 runs at about 20-25 dKh which would be almost 2 full syringes at 5 mL water.

[lewismw]

AAHH HA!! Thank you RokleM!

I was looking at the test backwards! I have been using a full syringe effectively taking me higher than the test would allow not to the bottom end of Zero. Wow what an idiot!
Ok so i was not crazy thinking that the reactor was not breaking down the medium at all, in fact the more i cranked up the c02 the more off the scale was going!!!!! LOL!!!!!!
My dang tank alk is around 20dkH now AAAHHH!!!

[RokleM]

Yes, if your tank is 20 dkH, shut off the reactor immediately and let it come down slowly for a few days. Keep an eye on things.

[lewismw]

ok i just triple checked and my tanks DKH = 11.3. So i gues ia m at the very high end of where i want to be.
Thanks for helping me look past my own stupidity RokleM!

I have lowered the C02BPM and my effluent tests at ~23Dkh (not -5 LOL!).

BTW where do you keep the Ph of the effluent on your 618? I see some want to keep b/w 6.7.6.9 and i have been aiming for 6.5.......

[RokleM]

Depends on the media. There is a large GEO thread that is worth the read (believe someone linked it in one of your other posts). I keep my chamber at 6.5 as I'm running the large grain GenX media. Arm users typically keep it a bit higher as it has a tenancy to melt at lower pH levels.