High magnesium depletion

richard.oberholzer.923 · Jul 25, 2015

Hi guys and girls.

I am only been reefing for just over a year now and would like to know if my dosing sounds right.

Tank is a 800l in total
1250×800×600
200l sump running at half
Overflow box to sump
2 skimmers
1 biopellet reactor
5000l Return pump feeding the reactor
DSB that's 6 weeks old
T5+led light
Inhabitants
Fox Naso hippo scopaz 2 clowns 2 yellow tail damsels 3 yellow damsels 1 leopard wrasse coral beauty 1 anthia 3 cleaner shrimp 6 hermit crabs

2 hammer coral . Colt. 2 plate corals. 4 mushroom. green leather. green button clove . trumpet. cup. cabbage

Parameters

KH-7.3
MAG-1180
CAL-440
Po4 -0.03
No3-25
Sr- 2

I dose daily
30ml aqua vitro eight four
2g seachem advantage calcium
15g seachem advantage magnesium

does this look normal? Am I doing something wrong? Here is a photo of my tank if it helps.

Randy Holmes-Farley · Jul 25, 2015

No, it doesn't look normal. Actual magnesium demand is usually about 1/10 the calcium demand, and cannot really be much higher EXCEPT if the levels are being messed with by water changes.

What salt mix are you using? Which test kits?

KJ · Jul 25, 2015

Do-It-Yourself Magnesium Supplements for the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com

richard.oberholzer.923 · Jul 25, 2015

Coral pro 200l once a month WC and salifert kits and I use RODI.

richard.oberholzer.923 · Jul 25, 2015

Thanks kj took me the better part of the day to read and understand it. That's why I came to ask if my tank sounds normal as all tanks are different and mine sounds wrong.

Randy Holmes-Farley · Jul 25, 2015

richard.oberholzer.923 said:
Coral pro 200l once a month WC and salifert kits and I use RODI.

What salinity and how are you measuring that?

Red Sea Coral Pro at 35 ppt should have magnesium well above 1400 ppm. It didn't get depleted down to what you have now, so perhaps it is testing error, a bad or inhomogeneous batch, or low salinity.

richard.oberholzer.923 · Jul 25, 2015

0.024 I use a RSK refractometer and calibrated it last week. My wc is due tomorrow should I do a bigger wc at 0.025 About 2 buckets (22 kg) back I used seachem reef salt and started having to dose magnesium after that.

Randy Holmes-Farley · Jul 25, 2015

Try measuring some of the new salt mix. Maybe the testing is off.

richard.oberholzer.923 · Jul 25, 2015

Just tested with new kit as my old one was almost finish and is at 1260 and I just added 20g magnesium 4 hours ago.

Randy Holmes-Farley · Jul 25, 2015

OK, that's more reasonable, but still seemingly lower than expected.

KJ · Jul 25, 2015

richard.oberholzer.923 said:
Thanks kj took me the better part of the day to read and understand it. That's why I came to ask if my tank sounds normal as all tanks are different and mine sounds wrong.

YW

richard.oberholzer.923 · Jul 25, 2015

Randy Holmes-Farley said:
Try measuring some of the new salt mix. Maybe the testing is off.

I managed to test newly mixed salt and reads mag 1300 at 0.026 and 22 degrees. Bucket states 1340 ppm. Also anly mixed 1L. Should I get my mag higher to balance things out?