Perplexing test results.

[stanleo]

I have some questions. 120 gallon mixed reef with crabs, snails, a shrimp, 1 birdsnest about the size of a softball added 2 months ago, 1 hammer bigger than a golf ball added 5 months ago, GSP add 8 months ago, kenya tree and mushroom added a month ago, toadstool added 8 months ago, and zenia added 5 months ago. I added a montipora just this week. Sump with filter socks, skimmer and seperate ten gallon refugium with chaeto fed from the sump. Water change every two weeks like clock work with 24 gallons of temp and salinity matched water using Instant Ocean Reef Crystals. Salt mixes high with magnesium 1600 and calcium 500. Tank has been running for 10 months.

All the corals are growing well, hammer has two new heads, birdsnest is doing great and the softies are growing like weeds. With the exception of the toadstool but I attribute that to me moving it all the time cause I was trying to find the right place for it. I don't move any of the others.

Inverts seem to do really well. I haven't had the shrimp that long so I haven't seen any sheds yet.

I test alk almost daily and the others weekly. Just started weekly, before it was just every two weeks prior to water change. I haven't needed to dose calcium but last month I started dosing Reef 2 of Seachem Fusion for alkalinity almost daily. Here is the progression

Oct 8 (water change that day)
pH 8 (API)
Phosphate 0 (API)
KH 10 (Red Sea)
Calcium 550 (Red Sea)
Magnesium 1600 (Red Sea)

Oct 15
pH 8(API)
dKH 7.4(Red Sea)
Calcium 500ppm (Red Sea)
Magnesium 1440 (Red Sea)
Nitrate 2ppm (Salifert)
Phosphate .03ppm (Salifert

Oct 18
dKH was 7.8
Calcium was 500ppm
Magnesium 1440ppm
This is when I started dosing for alkalinity.

Oct 22 (water change that day)
pH 8.2 (API)
Nitrate 2ppm (Salifert)
Phosphate .03ppm (Salifert)
Alkalinity 10.4 (Red Sea)
Calcium 500ppm (Red Sea)
Magnesium 1600ppm (Red Sea)

Oct 30
Temp 78F
Salinity 35 ppt
pH 8.2 API
Alkalinity 9 dKH Red Sea
Calcium 500 ppm Red Sea
Magnesium 1440 ppm Red Sea
Phosphate .03 ppm Salifert
Nitrate 2 ppm Salifert

Nov 5 (water change that day)
Temp 78F
Salinity 35 ppt
pH 8.2 API
Alkalinity 9 dKH Red Sea
Calcium 470 ppm Red Sea
Magnesium 1440 ppm Red Sea
Phosphate .1 ppm Salifert
Nitrate 2 ppm Salifert

Nov 10
Temp 78F
Salinity 35 ppt
pH 8.2 API
Alkalinity 8.4 dKH Red Sea
Calcium 440 ppm Red Sea
Magnesium 1520 ppm Red Sea
Phosphate is between .03 and .1 ppm Salifert
Nitrate 2 ppm Salifert

Today Nov 19 (water change today)

Temp 78F
Salinity 35 ppt
pH 8.1 API
Alkalinity 8.4 dKH Red Sea
Calcium 470 or 440 ppm Red Sea
Magnesium 1440 ppm Red Sea
Phosphate is between .03 and .1 ppm Salifert
Nitrate 2 ppm Salifert
I ran this calcium test 4 times with two different syringes cleaning everything in between with RO water. 2 tests at 470 and 2 at 440

Can people who understand test results better than me look at this progression and tell me your thoughts?

Am I overthinking it? I would think at this time with corals clearly growing that Magnesium and calcium would be getting used so by now I would have to start dosing this stuff. Should I not worry too much since I do have corals growing and very little algae growth in the DT?

I know this was ridiculously long and I thank you if you made it all the way through.

Would you be doing anything different than me?

This is the most recent tank shot. Taken 11/12

 

[stanleo]

Build Thread - Stanleo's 120 gl mixed reef

Well better late than never. I started this build January 15, 2019 and I am just now starting this journal so I will try to give a time line with pics as best I can. Tank is a 120 gallon standard that we got used from the LFS with the stand. 48"x24"x24". Heater is an Eheim. Sorry I don't...

www.reef2reef.com

There is a link to my build thread if that helps. Thanks guys.

 

[nereefpat]

It's good that you have started dosing to keep alkalinity stable.

It's common when people begin dosing to only have to dose alk, and water changes take care of Ca and Mg. Every 1 dKH equates to about 7ppm Ca, and very little Mg.

Does that help?

 

[madweazl]

It is being used and your test results are showing you that each parameter is continuing to get lower and lower with time.

Your alkalinity started at 10 dKh and is now 8.4. Your calcium started at 500 and is now 440-470. Your magnesium started at 1600 and is now 1440. You are essentially "dosing" because each water changes you're introducing has the higher levels of alkalinity, calcium, and magnesium. Each time you do the water change, it buffers the tank water slightly but the following week the levels drop a bit (until you perform another water change).

If you want to keep it stable at the levels your salt mixes up to, you'll need to dose to the levels of your salt mix (I'm assuming close to 10 dKh, 500ppm calcium, and 1600ppm magnesium), otherwise, you'll see the variations you're getting now.

 

[stanleo]

It is being used and your test results are showing you that each parameter is continuing to get lower and lower with time.

Your alkalinity started at 10 dKh and is now 8.4. Your calcium started at 500 and is now 440-470. Your magnesium started at 1600 and is now 1440. You are essentially "dosing" because each water changes you're introducing has the higher levels of alkalinity, calcium, and magnesium. Each time you do the water change, it buffers the tank water slightly but the following week the levels drop a bit (until you perform another water change).

If you want to keep it stable at the levels your salt mixes up to, you'll need to dose to the levels of your salt mix (I'm assuming close to 10 dKh, 500ppm calcium, and 1600ppm magnesium), otherwise, you'll see the variations you're getting now.

Thank you, I think you are right. I have been testing still and it is slowly going down between water changes. You and the others helped me make sense of it.