Calcium reactor and tank PH

[spaulr]

I read the other setup threads about setting up the korallin 1502 but still have a few questions. I have a 40 gallon with LPS, SPS with a 15 gallon sump. I'm worried about the PH of the effluent dropping my TANK ph below 7.8. I did have the effluent's ph at 6.7. I'm going to try and set it to 7.0. Will this be low enough to dissolve the ARM media that I'm using? Also, I'm moding my Aqua C ev90 skimmer will a quick connect JG fitting to run the effuluent straight into the skimmer intake to help off gas the C02. Aqua C already said this was ok.

What is a good tank PH to have with a Ca reactor - 7.8-8.0? Do you also "dose" something else to counter act the ph of the effluent?

 

[Anonymous]

>...Do you also "dose" something else to counter act the ph of the effluent?

Since the pH effect of the eff. is not permeant, don't dose anything, but rather a one-shoot deal. Some, however, are running kalk to counteract the effect in pH. IMO, all you need to do is to make sure the eff. is drip near a high flow area of your sump, and the EV90 should be able to do all the gas exchange for you there. Just make sure the skimmer air intake has access to fresh air.

 

[Len]

I used to run kalk to offset my Ca reactor. I was able to maintain a pH of 8.2 to 8.3 with both. Without the kalk reactor, my pH is consistently at 8.0-8.1 during the day (dips to 7.7 at night). Everything is fine in my tank.

 

[spaulr]

That sounds great. My reactor is running about 11 bubbles per min and 60 drops of efluent per minute. PH of the effluent is 6.65. I'm trying to get my PH controller working correctly (to turn off the C02 if the effluent ph dips below 6.8 and turn it on above 7.0), but I have a feeling there may be a Firmware bug in the latest release of the RKII.

Haven't tested any parameters at this point, I'm just trying to dial in the effluent PH and get that stable. Once I do that, then I'll worry about KH and Ca of the tank. I'll probably do a water change, adjust with Randy Holmes solution and go from there.

 

[spaulr]

On the PH note, what is the MIN of PH you should let your tank get to? Meaning, where it starts having a very BAD effect on the corals and fish? I know everyone shoots for 8.1 < PH < 8.4 because that's the optimal range for calcification to occur, but how low is to low? Until my controller is working properly I'm considering turning the C02 off at night and having it only come on during the day. I'd hate to wake up and see a ph of 7.2. I'd need a new pair of shorts

 

[DBW]

A pH (note the lack of capitalisation of the "p") of 7.8-7.9 is not something to worry about for a tank if that is the low point over night. Not the best and something you should try to improve gas exchange if your alkalinity is fine, but nothing to really stress over.

With a calcium reactor, it is best if you return the effluent into a region where the excess carbon dioxide in it will be transfered out. Great place is to fed into your protein skimmer, due to the high turbulence and good gas exchange that occurs inside. If you still have low pH issues, then you have to start looking at gas exchange, including water movement within the tank, air exchange between the top of the tank and the room, and the room and the atmosphere outside the house.

 

[ZooKeeper1]

True, but remember the reactor is still adding alkalinity as bicarbonate, so no ammount of aeration will make the effluent not lower the pH. It's temporary, but the reactor adds it continuosly so it's going to be lower than what it is before the reactor was added.

 

[DBW]

Note quite true. Aeration will increase the pH of the effluent. It has to, since it has excess carbon dioxide in it, with depresses the pH. There is a limit to the point at which it will increase, depending on time and a few other factors.

 

[ZooKeeper1]

Right. I was thinking of the fact that even if you get the excess Co2 out of the effluent before it got in the tank, it would still be undergoing the conversion from bicarb to carbonate in the tank which will still cause a lowering effect on the tank.

Fact it that even with two chamber reactors and dripping the effluent into a high flow area the average user experiences a drop in pH.

 

[spaulr]

Thanks, I still haven't got around to drilling and tapping the skimmer. I've been practicing on a piece of scrap plexi. I'm still not proficient enough to NOT be freaking out when I do it to the skimmer.
Even with the Ca reactor running I haven't seen my pH dip below 7.9, but then I also haven't seen it get about 8.2 during the day. Gas exchange should be pretty darn good as I have an open back stand 1 foot from 2 windows that are open all day, plus 2 fans in the canopy during the day - I only run 1 at night to save some power.

What would I gain by adding a second chamber to the reactor? FYI- this is my first experience with a Ca reactor. I mainly dosed 2 part solution and maintained very limited corals. I also notice that even with 10 bubbles a minute, CO2 seems to be building up at the top of the chamber (Korallin 1502) - even with the use of the recommeded lifter pump. Would a second chamber help to eliminate that as well?