boobookitty
Active member
Also posted in the reef forum.
I have a 400G, about 3 years old. I've had reef tanks for 20+ years, including a 240G for a decade that did very well. Took it down 6 years ago, started the 400G 3 years after.
The problem is my pH. It's swings between 7.85 during the day down to 7.65 at night, sometimes down to below 7.6. I know not to chase numbers, but that seems reeeeaally low, and I've suffered for a year and a half from periodic coral colony rtn's (good growth until then), sometimes part of a colony, sometimes the whole thing, and I think it's related.
Basic equipment
- 400G tank, 100G sump/fuge
- 8 Radion 30 pros, 20KK profile
- flow provided by Vectra L1 return on a sea swirl (old school!), an MP60, 3 Wavs, and a Panta Rhei.
- Dastaco CA reactor
- SRO Ext-6000 skimmer
- vodka dosing for control of nitrate
- GFO for control of phosphate
Parameters:
- alk 8.0
- CA 450
- Mg 1450
- Nitrate 1ppm
- phosphate 0.15 (been slowly lowering it from 1.5 6 months ago)
I had a nutrient problem that built up over a couple years; tried controlling it with zeovit, which worked well on my old tank but not on this one, and switched to vodka dosing and GFO, which has worked well to substantially lower them. I had thought the stn problem might have been that, but even with lower nutrient I have this issue.
Over the last few weeks I've tried to get the pH issue in hand:
- I've had tubing providing outside air as the skimmer air intake for a year or so; added CO2 scrubbing to it; this helped a little, but still left me with 7.65 at night
- punched a hole through my wall to the outside a couple weeks ago and have fresh air flowing across the top of the tank; this raised pH minimally, around 0.05
- flowed the fresh outside air across the sump; this didn't raise pH at all
- Dastaco's can deliver CO2 through the effluent return, so I had this drop into a tube that flows into the sump to try to avoid CO2 getting into the sump area; a few days ago I added a funnel to the tubing and raised the effluent return an inch, and added a fan blowing across the funnel to keep CO2 from settling into the sump; this actually helped some, around +0.05 pH
Even with all of the above, the best I can get pH during the day is 7.89-7.9, and at night it still can drop below 7.7. Very frustrating. Looking for input regarding any other ideas. I'd prefer not to go to a chemical solution like kalk, but I will if that becomes the only option.
I have a 400G, about 3 years old. I've had reef tanks for 20+ years, including a 240G for a decade that did very well. Took it down 6 years ago, started the 400G 3 years after.
The problem is my pH. It's swings between 7.85 during the day down to 7.65 at night, sometimes down to below 7.6. I know not to chase numbers, but that seems reeeeaally low, and I've suffered for a year and a half from periodic coral colony rtn's (good growth until then), sometimes part of a colony, sometimes the whole thing, and I think it's related.
Basic equipment
- 400G tank, 100G sump/fuge
- 8 Radion 30 pros, 20KK profile
- flow provided by Vectra L1 return on a sea swirl (old school!), an MP60, 3 Wavs, and a Panta Rhei.
- Dastaco CA reactor
- SRO Ext-6000 skimmer
- vodka dosing for control of nitrate
- GFO for control of phosphate
Parameters:
- alk 8.0
- CA 450
- Mg 1450
- Nitrate 1ppm
- phosphate 0.15 (been slowly lowering it from 1.5 6 months ago)
I had a nutrient problem that built up over a couple years; tried controlling it with zeovit, which worked well on my old tank but not on this one, and switched to vodka dosing and GFO, which has worked well to substantially lower them. I had thought the stn problem might have been that, but even with lower nutrient I have this issue.
Over the last few weeks I've tried to get the pH issue in hand:
- I've had tubing providing outside air as the skimmer air intake for a year or so; added CO2 scrubbing to it; this helped a little, but still left me with 7.65 at night
- punched a hole through my wall to the outside a couple weeks ago and have fresh air flowing across the top of the tank; this raised pH minimally, around 0.05
- flowed the fresh outside air across the sump; this didn't raise pH at all
- Dastaco's can deliver CO2 through the effluent return, so I had this drop into a tube that flows into the sump to try to avoid CO2 getting into the sump area; a few days ago I added a funnel to the tubing and raised the effluent return an inch, and added a fan blowing across the funnel to keep CO2 from settling into the sump; this actually helped some, around +0.05 pH
Even with all of the above, the best I can get pH during the day is 7.89-7.9, and at night it still can drop below 7.7. Very frustrating. Looking for input regarding any other ideas. I'd prefer not to go to a chemical solution like kalk, but I will if that becomes the only option.
