I’m going to bump this thread as I could use some input here. I have a friend with a 150 gallon system setup in his garage. He’s got a bunch of smaller coral frags in it with minimal growth but they are growing.
This system has been up for about 2 years now with next to no load. He recently started adding SPS frags to it. They all seem to be doing ok and showing signs of growth. He had not been testing the Alk in this tank. When he tested a few days ago his Alk was low.
pH is reading 8.3-8.4
Calcium 500
Mg 1500 (kind of high IMO)
Salinity 1.024
PO4 is reading 0 according to the Hanna ULR. Since there are only a couple fish in there, I am not terribly surprised.
A few days back, he tested his Alk and it was around 6.5 DKH. I told him he needed to add some alk supplement but before I could give him instructions, he grabbed some of his Bionic 2 part which is the calcium version and added 75ml of the Alk part as a knee jerk reaction. Of course, this spiked his pH up to 8.6 and the Alk temporally jumped to 8.5 but fell the next morning down to around 7.8 DKH several hours later and the next day down to 7.2 DKH.
After 24 hours, I had him break out the BRS Sodium Bicarbonate. I used the reef chemistry calculator and based on an Alk of 7.2DKH, 2.8 tsp would be needed to raise the alk from 7.2 to 8.0. I told this friend to mix 5 tsp of BRS Sodium Bicarb into a gallon jug of RODI. He’s not great at taking direction. He’s been in the hobby for well over 30 years and is “old school” so to speak. So he goes and grabs a metal teaspoon from his drawer. Not an actual measuring spoon and dumps 5 spoonfuls into a 5 gallon bucket and proceeds to add “some” water to it. Apparently he added 1/5th of the bucket of RODI according to his estimate which I didn’t find out until I went there yesterday. I now estimate that to be about 2 gallons worth of water with probably closer to 6 or 7 tsp of bicarbonate. Anyhow, a few nights ago I told him to add 4 cups of this solution to his tank that evening when his alk had dropped back to 7.2. He adds it to his sump and retests hours later. The Alk didn’t seem to respond. I had him add 4 more cups the next morning. He retests that afternoon and still no change. I went over there yesterday and I realized that his estimate of gallon was more like 2 gallons so I estimate that he may have added about 1-2 tsp of bicarbonate to his system in the 24 hours prior. I explained that we needed to precise. I proceeded to dump his bucket of mixture which probably had about a gallon left in it.
So now that I was there, it was back to square 1. I grabbed a jug and an actual measuring spoon. We proceeded to add 5 TSP of the bicarbonate to 1 gallon like I had instructed. We added 2 cups of that mixture to the sump and I noted what appeared to be precipitate in the water column immediately afterwards. I would have expected his Alk to reach around 7.5-7.6 with that dose. Perhaps we should have dosed directly in the display. That said, he tested the alk a few hours later using a Salifert test kit and the Alk was still the same. He tested again this morning and it was still at 7.2. Now it’s possible there has been some alk consumption overnight but the precipitate I noted yesterday raised my concerns. I wanted to start with a weak alk solution rather than doing the full strong @Randy Holmes-Farley Part 2 solution while we try to get a grip on his Alk before automating it with a doser. I’m just concerned that the high pH and or even the lack of Po4 could be causing an issue with getting the Alk levels higher as we were aiming for 8-8.5 as a target DKH.
My observation seems to have me thinking that the tank isn’t responding to the addition of the sodium bicarbonate but it could be that we just need to increase the amount we are adding. I just don’t want to risk his corals and add to much alk solution. Any feedback would be appreciated. I’m used to my calcium reactor and it’s not often that I’ve encountered reef tanks with naturally high pH levels like this and cases where it seems the tank doesn’t respond to dosing the alk part.
This system has been up for about 2 years now with next to no load. He recently started adding SPS frags to it. They all seem to be doing ok and showing signs of growth. He had not been testing the Alk in this tank. When he tested a few days ago his Alk was low.
pH is reading 8.3-8.4
Calcium 500
Mg 1500 (kind of high IMO)
Salinity 1.024
PO4 is reading 0 according to the Hanna ULR. Since there are only a couple fish in there, I am not terribly surprised.
A few days back, he tested his Alk and it was around 6.5 DKH. I told him he needed to add some alk supplement but before I could give him instructions, he grabbed some of his Bionic 2 part which is the calcium version and added 75ml of the Alk part as a knee jerk reaction. Of course, this spiked his pH up to 8.6 and the Alk temporally jumped to 8.5 but fell the next morning down to around 7.8 DKH several hours later and the next day down to 7.2 DKH.
After 24 hours, I had him break out the BRS Sodium Bicarbonate. I used the reef chemistry calculator and based on an Alk of 7.2DKH, 2.8 tsp would be needed to raise the alk from 7.2 to 8.0. I told this friend to mix 5 tsp of BRS Sodium Bicarb into a gallon jug of RODI. He’s not great at taking direction. He’s been in the hobby for well over 30 years and is “old school” so to speak. So he goes and grabs a metal teaspoon from his drawer. Not an actual measuring spoon and dumps 5 spoonfuls into a 5 gallon bucket and proceeds to add “some” water to it. Apparently he added 1/5th of the bucket of RODI according to his estimate which I didn’t find out until I went there yesterday. I now estimate that to be about 2 gallons worth of water with probably closer to 6 or 7 tsp of bicarbonate. Anyhow, a few nights ago I told him to add 4 cups of this solution to his tank that evening when his alk had dropped back to 7.2. He adds it to his sump and retests hours later. The Alk didn’t seem to respond. I had him add 4 more cups the next morning. He retests that afternoon and still no change. I went over there yesterday and I realized that his estimate of gallon was more like 2 gallons so I estimate that he may have added about 1-2 tsp of bicarbonate to his system in the 24 hours prior. I explained that we needed to precise. I proceeded to dump his bucket of mixture which probably had about a gallon left in it.
So now that I was there, it was back to square 1. I grabbed a jug and an actual measuring spoon. We proceeded to add 5 TSP of the bicarbonate to 1 gallon like I had instructed. We added 2 cups of that mixture to the sump and I noted what appeared to be precipitate in the water column immediately afterwards. I would have expected his Alk to reach around 7.5-7.6 with that dose. Perhaps we should have dosed directly in the display. That said, he tested the alk a few hours later using a Salifert test kit and the Alk was still the same. He tested again this morning and it was still at 7.2. Now it’s possible there has been some alk consumption overnight but the precipitate I noted yesterday raised my concerns. I wanted to start with a weak alk solution rather than doing the full strong @Randy Holmes-Farley Part 2 solution while we try to get a grip on his Alk before automating it with a doser. I’m just concerned that the high pH and or even the lack of Po4 could be causing an issue with getting the Alk levels higher as we were aiming for 8-8.5 as a target DKH.
My observation seems to have me thinking that the tank isn’t responding to the addition of the sodium bicarbonate but it could be that we just need to increase the amount we are adding. I just don’t want to risk his corals and add to much alk solution. Any feedback would be appreciated. I’m used to my calcium reactor and it’s not often that I’ve encountered reef tanks with naturally high pH levels like this and cases where it seems the tank doesn’t respond to dosing the alk part.
