can't maintain alkalinity
 

so i've got a marinetech ca reactor and it pumps out the Ca...levels are constantly high...as in > 450ppm. alk however is constantly low...like < 7dKH. i've tried every combination of adjustment that i can make with effluent and co2 but cannot maintain my alk. salt mix i use has low alk (6.5-ish) so i've been boosting this before it hits the tank but am i under any illusions that this reactor should be able to maintain alk levels?

appreciate any input...

ps my mg levels are good at around 1380-1450ppm.

With the calcium levels up so high you may be getting some precipitation happening dropping the alk part. I would stop the calcium reactor for a few days, bring the alk level back up to where you want it and when the calcium drops down to 400 start fiddling with the reactor again.:biggrin:

good idea...i'll give it a shot! thanks for the idea.

It's going to be very difficult to bring ALK up with your Reactor. I would get a large box of Bakeing soda and Boraxo mix it 2 parts Bakeing Soda to 1 part Boraxo and dose that to get your ALK back in line.

I would also check your salt in a fresh mixed batch of Water measure the ALK there to ensure you are starting off right.

You should use your Reactor to maintain CA and ALK not to raise it

J

yup...that's the truth i guess! get my parameters straight in my tank and in my change water then i suppose the reactor will be able to maintain...

thanks J,

No Prob D.
I have the exact same problem right now.

J

Having a low magnesium level will likely affect this as well, try keeping magnesium at 1350-1400.

Daryll,

Im gonna head out on a limb and disagree with some here.
There is definatly something else wrong, The reactor the size of the one you have will have no problem maintaining alk in a 300g system packed with SPS. Let alone a 120.
Your Reactor is an Alkalinity reactor...i dont even know why they call it a ca reactor.

It is much easier to raise alk with the reactor than it is calcium, they both come out of it in certain ratio`s. Alk being the major portion.

Most systems will see their alk top out long before they reach the calcium they wish to see, using a reactor..as is the case with my system.

My alk gets so high, i have temorarily shut the reactor down.
I will hit an alk of high 4`s meq/l long before a Ca of 400 is hit.
This is why many will also use a calcium additive to try and boost Ca without the added alk, this is why i have to run Kalkwasser aswell.
The reverse is true for Kalk, though it adds both aswell.

-What is the Ph Coming out of the reactor ?
- what is the Ca coming out of the reactor ?
- what is the alk coming out of the reactor ?
- what is your current effluent rate ?
- what is your current bubble count ?
-is the recirc pump on the reactor running ?

You mention fiddling with different rates...are you leaving it 48 hrs before the tank test is done ?
If the alk is low (out of the reactor) and the PH is above 6.5, then the only adjustment needed is more co2.



If we determine a few of these answers, we will find were the problem lies.

Marc.

That's why I think there is some precipitation happening. he could be bumping both levels up so high by adding so much that he is knocking alk out of the solution.
Sometimes it's good to get back to basics, stop running the reactor, bring both calcium and alk back to where they should be and start over slowly with the reactor :mrgreen:

I agree marie,

But he hasnt listed his current effluent values...i didnt want to say shut it down if that isnt the source of the low values.

Since this is the reverse of what happens with most reactors, im thinking its dialed in incorrectly or...a something totally outside the reactor that are the culprit that havent been mentioned yet.

-heavy stocking ?
-small or inconsistant water changes ?
-low alk salt, wich already has been determined as part of the problem.
-overfeeding ?