five.five-six
Well-known member
Things that happen quickly in a reef tank are almost never good.
Patience.
Patience.
Vodka dosing maxed out...best way to run GFO?
- Thread starter boobookitty
- Start date
boobookitty
Active member
Heh. I've been reef keeping for 20+ years...patience is a requirement.
boobookitty
Active member
An update. As predicted, the leaching took a while. I've gone through a good amount of GFO, but phosphates are down to around 0.1 or so, depending on when I change media. Which leads me to a question...
I'm using the BRS reactor and high-capacity media. I've noticed that when I change the media, the phosphates go down a good amount, then plateau, then start to slowly rise for a few days despite the water from the reactor still reading 0.0. For example, my last media change brought the tank levels down to 0.03 the next day, but then they slowly climbed back up to 0.12 over the next 3-4 days, even though testing of the output from the reactor showed it still at 0.0. Then the next media change dragged it quickly down to 0.03-0.04 again.
Is this normal? I'm I still experiencing some minor leaching, and eventually it'll settle down? Very happy to have the tank to a lower level (remember, I started at about 1.5), but I'd like to go more than 3-4 days before replacing the (somewhat expensive) media...
I'm using the BRS reactor and high-capacity media. I've noticed that when I change the media, the phosphates go down a good amount, then plateau, then start to slowly rise for a few days despite the water from the reactor still reading 0.0. For example, my last media change brought the tank levels down to 0.03 the next day, but then they slowly climbed back up to 0.12 over the next 3-4 days, even though testing of the output from the reactor showed it still at 0.0. Then the next media change dragged it quickly down to 0.03-0.04 again.
Is this normal? I'm I still experiencing some minor leaching, and eventually it'll settle down? Very happy to have the tank to a lower level (remember, I started at about 1.5), but I'd like to go more than 3-4 days before replacing the (somewhat expensive) media...
reefgeezer
Active member
Leaching may continue for a long time. Many are using Lanthanum Chloride to maintain phosphate levels. It's simple & inexpensive but has some risks. You could also add potassium nitrate and increase you carbon dosing. This will cause more nitrates to be bound and/or exported & take some phosphates with it. I'd read up on both processes and know the risks and rewards prior to starting. Finally, you can regenerate GFO. It involves acid so care is required, but it can certainly reduce costs.
Also , depending on the maturity of your tank, 0.1 ppm of phosphate may not be high at all. Do you have algae issues or slow coral growth? If not, maybe just try to maintain the level rather than trying to lower it. You might want to let nitrates rise a little if maintaining phosphates at about .1 ppm. IMO, the "balance" is as important as the number.
boobookitty
Active member
I'm actually ok with phosphates at around 0.1, considering from where I started. The phenomenon of tank phosphates dropping when media is replaced, then slowly rising again even though reactor output stays at zero (indicating media isn't exhausted) was unexpected to me.
I am not sure why the level still is rising if the output from the reactor is zero. Maybe some input (such as food) isn't getting removed quickly enough, but I don't see how that would lead to a rising level. It sounds as if the media is being exhausted, which would indicate that the changes should be fairly small, possibly within testing limits.
boobookitty
Active member
Yeah, it’s a bit odd. Changed the media yesterday even though reactor output was still showing 0, and as usual tank phosphate dropped overnight from 0.12 to 0.0. I fully expect it to slowly rise over the next 3-4 days back to 0.12 even with reactor output showing 0. Just a weird phenomenon.
reefgeezer
Active member
It could be as simple as the dilution rate of the 0 ppm water from the reactor doesn't keep up with the leach rate of the rock. When the phosphate level is @ .12, equilibrium may have been reached. Once it starts falling there is a delay before the rock begins to leach as the water's phosphate level moves farther and farther from equilibrium. At some point, it may be just a matter of the leach rate exceeding the dilution rate.
boobookitty
Active member
But if the reactor output flow isn't changed, and the resulting water flowing out of the reactor consistently reads 0.0, how would it pull more out when the media is new as opposed to a day later? Obviously the reactor is pulling out whatever level of phosphate is in the input (tank) water, or it wouldn't read 0.0.
I don't know why the leaching rate of the rock would increase suddenly to cause the rise in the phosphate level. I think it should be proportional to the difference between the current ppm and the equilibrium concentration of phosphate, which would depend on the quantity in the rock available for dissolution.
