Evaluate my Parameters

zoasguy · 05/10/2016, 07:31 AM

This is a 20g mixed reef tank, mostly LPS, softies and zoas. No filtration other than DSB and liverock. Weekly 20% water changes, light feeding. No dosing other than PurpleUp and Phyto.

pH- 7.93 (10 am)
Salinity- 1.026
Calcium- 470
Alkalinity- 7.7
Magnesium- 1080
Nitrate- 0.2
Phosphate- .18

Do you see any room for improvement or concern?

dkeller_nc · 05/10/2016, 08:32 AM

Yes. Your magnesium is far too low. Seawater is about 1250 ppm in Mg, most of us keep our tank water's concentration in the 1300's. Too low of a magnesium concentration can promote abiotic precipitation of calcium carbonate, especially on hot surfaces like heaters and pump internals.

Your phosphate is higher than most of us would like, and could result in an algae growth issue if left that high. However, it shouldn't cause any issues with your corals.

One thing I'd suggest is either installing a skimmer, or going with higher % water changes long term. Many folks do run nano and pico tanks without skimmers, but tend to change large percentage amounts of a water weekly to keep nutrients down and minor/trace minerals up.

zoasguy · 05/10/2016, 10:15 AM

OK so I should test the magnesium of the saltwater I'm using, if it is around 1300, then just increase water changes to maintain magnesium and export phosphates?

Also could any of these parameters be a reason why I haven't been able to grow coralline algae? I just started dosing PurpleUp this week.

Sent from my SAMSUNG-SM-G900A using Tapatalk

dkeller_nc · 05/10/2016, 11:11 AM

Yes, typical salt mixes tend to have at least 1300 ppm Mg, though there are some exceptions. If you're going to go with higher % water changes, you may need to be careful about matching the temperature, specific gravity and alkalinity of your new saltwater to that of your tank to avoid shocking the animals.

zoasguy · 05/11/2016, 08:52 AM

I have not been matching the temperature as it only swings a couple degrees for a short while. Is this really detrimental?

dkeller_nc · 05/11/2016, 09:42 AM

Depends. If your change water is 65 degrees, your tank is 78 degrees and you perform a 50% water change, yeah, I'd personally be uncomfortable with that sort of swing.

But if your change water is 75 degrees, and your tank's at 78 degrees, I'd have no problem with a 50% change.

But - matching the alkalinity and specific gravity are bigger considerations for large water changes, in my opinion.

moatdaddy · 05/11/2016, 07:26 PM

manually dose magnesium from brs. its much cheaper than large water changes. also large water changes swing parameters which is apt to upset corals more than fish. It also can mess with your biological filtration. I would not recommend over 20% in 24 hours, and that is just my experience.

how often do you test for phosphates? If they continue to rise I would toss in a bag of phosguard only if they are that level and keep climbing. So maybe reduce feeding a bit, or more often small water changes to remove the excess nutrients.

Your magnesium is probably low because im guessing your purple up is working with the coralline?

Do you use a reef keeping app to monitor you water testing via chart? If not check out EZ Reef

zoasguy · 05/12/2016, 10:50 AM

Moat, my phosphates stay around that level. I would like to implement a night time coral feeding a couple times a week so perhaps PhosGuard is something I should look into.

As far as my magnesium being tied up in coralline growth, I have only started dosing PurpleUp this week, and have yet to see any precipitation on the glass.

I will look into the app you suggested. I was just going to use excel but my office subscription is out of date, hooray.

05/10/2016, 07:31 AM	#1
zoasguy Registered Member Join Date: Jan 2016 Posts: 66	Evaluate my Parameters This is a 20g mixed reef tank, mostly LPS, softies and zoas. No filtration other than DSB and liverock. Weekly 20% water changes, light feeding. No dosing other than PurpleUp and Phyto. pH- 7.93 (10 am) Salinity- 1.026 Calcium- 470 Alkalinity- 7.7 Magnesium- 1080 Nitrate- 0.2 Phosphate- .18 Do you see any room for improvement or concern?

05/10/2016, 08:32 AM	#2
dkeller_nc Registered Member Join Date: Mar 2013 Location: Central NC Posts: 5,062	Yes. Your magnesium is far too low. Seawater is about 1250 ppm in Mg, most of us keep our tank water's concentration in the 1300's. Too low of a magnesium concentration can promote abiotic precipitation of calcium carbonate, especially on hot surfaces like heaters and pump internals. Your phosphate is higher than most of us would like, and could result in an algae growth issue if left that high. However, it shouldn't cause any issues with your corals. One thing I'd suggest is either installing a skimmer, or going with higher % water changes long term. Many folks do run nano and pico tanks without skimmers, but tend to change large percentage amounts of a water weekly to keep nutrients down and minor/trace minerals up.

05/10/2016, 10:15 AM	#3
zoasguy Registered Member Join Date: Jan 2016 Posts: 66	OK so I should test the magnesium of the saltwater I'm using, if it is around 1300, then just increase water changes to maintain magnesium and export phosphates? Also could any of these parameters be a reason why I haven't been able to grow coralline algae? I just started dosing PurpleUp this week. Sent from my SAMSUNG-SM-G900A using Tapatalk

05/10/2016, 11:11 AM	#4
dkeller_nc Registered Member Join Date: Mar 2013 Location: Central NC Posts: 5,062	Yes, typical salt mixes tend to have at least 1300 ppm Mg, though there are some exceptions. If you're going to go with higher % water changes, you may need to be careful about matching the temperature, specific gravity and alkalinity of your new saltwater to that of your tank to avoid shocking the animals.

05/11/2016, 08:52 AM	#5
zoasguy Registered Member Join Date: Jan 2016 Posts: 66	I have not been matching the temperature as it only swings a couple degrees for a short while. Is this really detrimental?

05/11/2016, 09:42 AM	#6
dkeller_nc Registered Member Join Date: Mar 2013 Location: Central NC Posts: 5,062	Depends. If your change water is 65 degrees, your tank is 78 degrees and you perform a 50% water change, yeah, I'd personally be uncomfortable with that sort of swing. But if your change water is 75 degrees, and your tank's at 78 degrees, I'd have no problem with a 50% change. But - matching the alkalinity and specific gravity are bigger considerations for large water changes, in my opinion.

05/11/2016, 07:26 PM	#7
moatdaddy Registered Member Join Date: Mar 2006 Location: Panama City beach florida Posts: 848	manually dose magnesium from brs. its much cheaper than large water changes. also large water changes swing parameters which is apt to upset corals more than fish. It also can mess with your biological filtration. I would not recommend over 20% in 24 hours, and that is just my experience. how often do you test for phosphates? If they continue to rise I would toss in a bag of phosguard only if they are that level and keep climbing. So maybe reduce feeding a bit, or more often small water changes to remove the excess nutrients. Your magnesium is probably low because im guessing your purple up is working with the coralline? Do you use a reef keeping app to monitor you water testing via chart? If not check out EZ Reef

05/12/2016, 10:50 AM	#8
zoasguy Registered Member Join Date: Jan 2016 Posts: 66	Moat, my phosphates stay around that level. I would like to implement a night time coral feeding a couple times a week so perhaps PhosGuard is something I should look into. As far as my magnesium being tied up in coralline growth, I have only started dosing PurpleUp this week, and have yet to see any precipitation on the glass. I will look into the app you suggested. I was just going to use excel but my office subscription is out of date, hooray.