Controlling pH in both directions.....

[mhurley]

I've got a new Neptune controller that is going to get hooked to my existing Ca reactor (a Geo). I know that I hook the controller to a solenoid on the CO2 line...This controls pushing the pH down when necessary...But this raises 2 questions for me.

1. What if the pH is dead on, but the tank is low on Ca, the reactor wont be functioning and therefore wont raise the Ca, right?

2. What if the pH is low? How does it get raised since CO2 will only lower it.

Thanks,
mike

 

[kevinpo]

If the PH is low enough and the solenoid is off then the media will be dissolving in the reactor as the media dissolves the PH raises causing the solenoid to open. During this time water is always flowing through the media bringing dissolved media to the tank.

In most reactors (mine included) the solenoid is always open providing a constant bubble rate of around 40-100 bubbles per min.

HTH,
Kevin

 

[mhurley]

Kevin,

I'm confused.....I'm controlling the pH of my tank water, not the effluent of the reactor. My probe will be in the tank water. My assumption was when the pH of the tank got too high, the solenoid would open, injecting CO2 into the CA reactor, which would ultimatly lower the pH of the tank.

I agree with you about having constant bubbles, at least that what my tank does now...But I don't have a controller on it. Maybe my question was poorly phrased so I'll try again.

How does a pH controller control pH both up and down?

 

[kevinpo]

I haven't heard of a tank PH ever getting too high when using a calcium reactor. Normally the PH runs a bit on the low side 7.8-8.0. I have never seen any ill effects from this level PH. I add baking soda/washing soda for buffer which also raises my PH to 8.15-8.3. I haven't heard of anyone trying to control the PH of their tank using a calcium reactor as the controller. Sorry I couldn't be more help.

Regards,
Kevin

 

[peterlin98]

After adding calcium reactor, my PH is much lower (7.9-8.0) and I was worried. My ALK was high 14-16 dKH. While corals and clams look okay, I just had to do something. I purchased a Pinpoint PH controller. I think it's great to shut off CO2 output if there is power outtage - and I was concern that the PH to continue to drop at night. I did all of these after reading several threads/articles that suggest PH 7.8-8.0 is not too bad for a reef tank. The key is to keep things constant. Big swing of PH is bad for your animals.

To bring the PH up, I added another Ca doser from Tunze. This is a bottle filled with Kalk connected to a water pump. So that I'm dosing Kalk water at the same time of replacing top off water.

Back to you questions
1. What if the pH is dead on, but the tank is low on Ca, the reactor wont be functioning and therefore wont raise the Ca, right?

>> I agree with mhurley that low PH inside of Calcium reactor will continue to produce Ca - even after CO2 output is shut off by the PH controller. I am still checking Ca frequently so that I can supplement my tank with Ca. I keep 30+ clams and some SPS - so I expect them to use up alot of Ca.

2. What if the pH is low? How does it get raised since CO2 will only lower it.

>> I just bought a Nielson reactor from My Reef Creation. I think a water pump can be connected to the controller - so that when PH is low, water pump turns on and force kalk water to be released from Nielson reactor. This will bring up your PH.
However, i don't think this is necessarily if Nielson reactor is used with the water pump that replace your top off water.

HTH.
Peter

 

[peterlin98]

PS - I bought Nielson reactor from My Reef Creation (even though I already have something similar from Tunze) - This is because Tunze's version requies that you shake the bottle (filled with Kalk and water) regularly (by hand - Oh my gawd).

At first I thought water pump will keep the Kalk stir up - but I see the water push Kalk powder to one side of the container.

So - the Nielson reactor (with a power stir) should take care of that problem.

 

[Osama]

I have a 180g reef with a nielsen reator & a calcium reactor. I also have a Neptune Aquacontroller II. I have the Neptune controller programmed to shutoff the Litermeter pump that doses the Kalk from the Nielsen when the ph in the tank reaches 8.4 & togo back on when the pH drops to 8.2.
I also have my controller shut off the CO2 to the calcium reactor if for some odd reason the pH drops to 7.9 which does happen when my Kalk in the Nelsen is exhausted and I am too lazy to replenish the Kalk and as I am learning to fine tune my system. I hope this helps.

 

[mhurley]

Thanks Osama...That's what I needed to know. Where'd you get your Nielson?...Incidentally...when I get this 375 up and running....I'll be looking for frags (hint, hint).

Mike

 

[Osama]

Hi Mike; don't forget the pictures for the 375g.
I got my Nielsen from my reef creations. I got a specially ordered large one. I had trouble at the beginning with the stirrer bar but I am happy with it now. If you go that route ask Andy for wing nuts instead of screws to close the lid tight.and for a thin wear plate inside the acrylic tube which I believe he has incorporated in his designs now. Good Luck. See ou whenerver you are ready.I just got rid of my large centerece as it outgrew my tank & was touching the front glass & back rockwork.....

 

[dvb]

I have the same problem. I just bought the Aqua Controller Pro and also have a reactor. What I worked out was that my flow rate is a little higher than it was before I had the controller. Since most of the calcium is being used during the daytime when the lights are on, it is not too difficult to keep the ph and calcium in check.

In the morning my ph is about 8.06. The lights come on and my ph starts going up. When the ph hits 8.2, the CO2 starts and that keeps the ph from going up any more. The reactor is now adding calcium and the corals and clams are using up more during this time while the lights are on.

When the lights go off at 8 pm the ph is usually around 8.2. The controller shuts off the CO2 when the ph hits 8.15. Then the ph naturally drifts down to 8.05 or so by the time my lights come on the next day.

I had to add turbo calcium to get my calcium to the right level and then my reactor just maintains the desired level. I had to test the calcium every other day while this process was starting up.

Bob Goemans book "Water Quality Guidelines for the Marine Aquarium" is a really good book, which addresses calcium reactors and kalk additions, etc. It is a little bit detailed in parts, but very worthwhile. It is about 9 bucks.

 

[mhurley]

dvb,

That is an incredibly interesting concept! I just might have to try that out. I was going to buy/build a Nilsen reactor to handle upping the pH. Using Kalk and Ca would give me the best of both worlds, but means more $$$.

Thanks,
Mike

 

[randy holmes-farley]

Since most of the calcium is being used during the daytime when the lights are on,.


What makes you say that? It might be true, and we've had extensive discussion on the subject. Andy Hipkiss did some measurements a while back and got a seemingly different result (and rejected the idea of turning off the reactor):

http://www.reefcentral.net/vbulletin/sh ... +and+night

but I wondered if you had some other set of data that suggested this to be true. The literature data seems mixed.