Critique My Alk/Cal/Mag

[mjt82]

Did some testing just now and got these results:

Alk 10.1 (Hanna)
Cal 410 (Red Sea)
Mg 1200 (Red Sea)
pH 8.08 (Apex)

My tank consists of mostly softies and several LPS, with a few SPS (monti’s). I want to be more successful with the LPS and easy SPS. Softies and LPS look great, monti’s not so good (bleached), but I think I may not have acclimated them to my lights slowly enough (8x80w ATI sunpower).

How am I doing? Currently my parameters are maintained via kalk in my top off from a kalk reactor.

 

[XNavyDiver]

It's hard to say by just looking at the numbers. There are other factors involved, such as age of the tank, dry rock or live rock used?, par intensity of the lights...

 

[Randy Holmes-Farley Verified Community Expert]

If real, I'd raise the magnesium, but many people get readings with the Red Sea kit that do not agree with other kits.

Limewater as top off (good choice) will allow magnesium to decline so boosting it might be in order.

The others look fine, IMO, as long as nutrients (nitrate and phosphate) are not too low. Too low of nutrients at 10 dKH may stress SPS, as they may grow skeletons faster than they can add tissue (causing burnt tips).

 

[mjt82]

It's hard to say by just looking at the numbers. There are other factors involved, such as age of the tank, dry rock or live rock used?, par intensity of the lights...

Age of the tank: approximately 3 months. This is an upgrade, but the rock is new (dry pukani - cured appropriately for 3 mos,no phosphate issues)

I’m using a 6’ ATI Sunpower 8 bulb T5 fixture. Not sure on exact PAR/PER numbers. I am thinking about picking up a Seneye or borrowing a PAR meter to get an idea of exact numbers.

Thanks for the reply!

 

[mjt82]

If real, I'd raise the magnesium, but many people get readings with the Red Sea kit that do not agree with other kits.

Limewater as top off (good choice) will allow magnesium to decline so boosting it might be in order.

The others look fine, IMO, as long as nutrients (nitrate and phosphate) are not too low. Too low of nutrients at 10 dKH may stress SPS, as they may grow skeletons faster than they can add tissue (causing burnt tips).

Thanks for the reply!

What kit would you suggest I use for Mg?

I have some BRS Mg mixed and ready to add. Do you think I should add Mg based off of this result?

I’ve been battling 0 nitrate and super low phos (0.01 by Hanna ULR checker) by feeding heavier. I’m not too keen on dosing the stump remover nitrate additive at this point... I think I may be overskimming somewhat as well...

I’m fairly certain the lack of success I had with the monti’s (two caps and a spongeodes) is a result of placing them too high in the tank too soon. I may be wrong there, though.

 

[Randy Holmes-Farley Verified Community Expert]

What salt mix are you using and what salinity?

In a 3 month old tank, the magnesium hasn't drifted too much from the salt mix.

 

[XNavyDiver]

Age of the tank: approximately 3 months. This is an upgrade, but the rock is new (dry pukani - cured appropriately for 3 mos,no phosphate issues)

I’m using a 6’ ATI Sunpower 8 bulb T5 fixture. Not sure on exact PAR/PER numbers. I am thinking about picking up a Seneye or borrowing a PAR meter to get an idea of exact numbers.

Thanks for the reply!

Ok, well, it's a young tank with dry rock. It may struggle with sps for a while. I say "may", because it's not a total certainty, but your tank profile (I started with dry rock also) fits a pretty clear established pattern. My recommendation is to be patient, let it mature, don't let your nutrients stay a zero, and in time you will see sps corals doing better. In the mean time, high par and high alk can really stress sps.

 

[mjt82]

Ok, well, it's a young tank with dry rock. It may struggle with sps for a while. I say "may", because it's not a total certainty, but your tank profile (I started with dry rock also) fits a pretty clear established pattern. My recommendation is to be patient, let it mature, don't let your nutrients stay a zero, and in time you will see sps corals doing better. In the mean time, high par and high alk can really stress sps.

Ok! Can do. I’ve been upping the feedings to raise nitrate and phos (both very low - essentially zero - thanks to Prodibio...)... I’m having some algae show up now, but the fish, LPS, softies, zoas are all looking great. I’ll be more patient and try SPS later! Thanks!

 

[mjt82]

What salt mix are you using and what salinity?

In a 3 month old tank, the magnesium hasn't drifted too much from the salt mix.

It’s Fritz at 1.026.

 

[Randy Holmes-Farley Verified Community Expert]

Most users report a lot of magnesium in that mix. You might measure magnesium in new salt water if you have some still, but my best guess is you have plenty and the kit is off.

Salifert seems to be a good magnesium kit.

 

[mjt82]

Most users report a lot of magnesium in that mix. You might measure magnesium in new salt water if you have some still, but my best guess is you have plenty and the kit is off.

Salifert seems to be a good magnesium kit.

I’ll pick one up and check the newly mixed water to see how it reads!

 

[FlyinBryan]

If your Mg is reading that low you may have a low salinity. Also, I found Red Sea to read much higher then salifert test kits. I’ve used salifert exclusively.
Agreed with above, mg should be significantly higher. Closer to 1350. You’ll have an easier time keeping other elements inline with either salinity closer to 1.025 and mg elevated. Good luck!

 

[mjt82]

If your Mg is reading that low you may have a low salinity. Also, I found Red Sea to read much higher then salifert test kits. I’ve used salifert exclusively.
Agreed with above, mg should be significantly higher. Closer to 1350. You’ll have an easier time keeping other elements inline with either salinity closer to 1.025 and mg elevated. Good luck!

SG is 1.025 on a freshly calibrated refractometer.