Dj A-Ron
Active Member
Hi everyone, I am new to the saltwater side of the hobby but have a good amount of experience in freshwater. I actually talked my wife into letting me have both a freshwater and a saltwater aquarium in the living room which is very cool! The freshwater tank is a 44 gallon high tech planted tank with tons of plants and running CO2 injection. The saltwater tank is a 55 gallon Red Sea Reefer 250 that is in the same room about 6 feet away from the other tank and I have the sump plumbed into the basement below the living room.
I have had the saltwater tank set up for about 3 weeks and doing a fishless cycle. I have an Apex on the tank and followed all the steps to properly calibrate the probes of the Apex. Since I've had the Apex set up the PH has shown some extreme changes. At first the PH seemed to be around 7.5-7.6, I know reef tanks are supposed to sit between 7.8-8.4 so this was kind of concerning. Again, I don't have any live stock in the tank so I figured now was the time to play around and see if I could figure this out. My theory is that the CO2 that is injected into the planted tank is affecting the PH of the saltwater tank. Luckily its cooled down here in Michigan so I was able to open my windows for a whole day and the highest I seen the PH raise to was 7.88. If I close my windows in the house the PH will steadily lower back down into the the 7.5-7.6. I did try adding an air stone to the sump and watching for a couple days to see what happened. That didn't help much. Maybe just raised it by 0.02 but did seem to equalize the fluctuations a bit. I then added my skimmer to the sump just to see if the added air bubbles would oxygenate the water even more and force the CO2 out of the water. It did seem to help a little bit but not much.
If I can't have the windows open the PH now seems to 7.55 or so during the day. At night the PH seems to rise. Again, my theory is that at night the CO2 injection is turned off in the freshwater tank so the PH of the saltwater tank is able to climb.
i don't know if any of this info helps but here are some other details of things that I'm using and testing:
I am using Tropic Marin Pro salt. I am using a BRS 7 stage RODI system for my source water. I have a saltwater mixing station set up for all of this.
I have a DOS set up on the sump to do 1 gallon a day water changes. The tank is 54 gallons and the sump holds 11 gallons for a total of 65 gallons.
I have been doing a fishless cycle for 3 weeks now and have had the lights turned off all of the time.
I have a Vectra M2 return pump and two MP40's running in the tank at about 30% for water surface movement and gas exchange.
As I said before, I have had a skimmer running for almost a week to add more gas exchange (even though there is nothing to skim).
Salinity is 35ppt, Alk is usually 6.5-7.5, Calcium is 435,
I thought about maybe trying the BRS CO2 scrubber/reactor to see if that helped bring the PH up or maybe running a air line tube from outside to the skimmer (Not sure if this would eventually cause problems with Michigan's subzero temps in the winter). I also thought about setting up a separate refugium and trying different light schedules to see if that helped pull some of the CO2 out and bring PH up. I've also been researching Kalkwasser but I don't have any corals to take advantage of the kalk so didn't know if that would mess with the tank further without anything in the tank to consume the Kalkwasser...?
So I guess my questions are:
Should I be concerned about this ultra low PH?
Can the nitrogen cycle affect PH in this manner? Could the nitrogen cycle be the culprit of the low PH?
Do you think the CO2 injection in the freshwater tank is indeed elevating the CO2 in the room and indeed affecting the PH of the Saltwater tank?
Any suggestions would be greatly appreciated. Let me know if there is any additional information needed. I can attach photos of my set up if needed.
Thanks everyone
I have had the saltwater tank set up for about 3 weeks and doing a fishless cycle. I have an Apex on the tank and followed all the steps to properly calibrate the probes of the Apex. Since I've had the Apex set up the PH has shown some extreme changes. At first the PH seemed to be around 7.5-7.6, I know reef tanks are supposed to sit between 7.8-8.4 so this was kind of concerning. Again, I don't have any live stock in the tank so I figured now was the time to play around and see if I could figure this out. My theory is that the CO2 that is injected into the planted tank is affecting the PH of the saltwater tank. Luckily its cooled down here in Michigan so I was able to open my windows for a whole day and the highest I seen the PH raise to was 7.88. If I close my windows in the house the PH will steadily lower back down into the the 7.5-7.6. I did try adding an air stone to the sump and watching for a couple days to see what happened. That didn't help much. Maybe just raised it by 0.02 but did seem to equalize the fluctuations a bit. I then added my skimmer to the sump just to see if the added air bubbles would oxygenate the water even more and force the CO2 out of the water. It did seem to help a little bit but not much.
If I can't have the windows open the PH now seems to 7.55 or so during the day. At night the PH seems to rise. Again, my theory is that at night the CO2 injection is turned off in the freshwater tank so the PH of the saltwater tank is able to climb.
i don't know if any of this info helps but here are some other details of things that I'm using and testing:
I am using Tropic Marin Pro salt. I am using a BRS 7 stage RODI system for my source water. I have a saltwater mixing station set up for all of this.
I have a DOS set up on the sump to do 1 gallon a day water changes. The tank is 54 gallons and the sump holds 11 gallons for a total of 65 gallons.
I have been doing a fishless cycle for 3 weeks now and have had the lights turned off all of the time.
I have a Vectra M2 return pump and two MP40's running in the tank at about 30% for water surface movement and gas exchange.
As I said before, I have had a skimmer running for almost a week to add more gas exchange (even though there is nothing to skim).
Salinity is 35ppt, Alk is usually 6.5-7.5, Calcium is 435,
I thought about maybe trying the BRS CO2 scrubber/reactor to see if that helped bring the PH up or maybe running a air line tube from outside to the skimmer (Not sure if this would eventually cause problems with Michigan's subzero temps in the winter). I also thought about setting up a separate refugium and trying different light schedules to see if that helped pull some of the CO2 out and bring PH up. I've also been researching Kalkwasser but I don't have any corals to take advantage of the kalk so didn't know if that would mess with the tank further without anything in the tank to consume the Kalkwasser...?
So I guess my questions are:
Should I be concerned about this ultra low PH?
Can the nitrogen cycle affect PH in this manner? Could the nitrogen cycle be the culprit of the low PH?
Do you think the CO2 injection in the freshwater tank is indeed elevating the CO2 in the room and indeed affecting the PH of the Saltwater tank?
Any suggestions would be greatly appreciated. Let me know if there is any additional information needed. I can attach photos of my set up if needed.
Thanks everyone
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