What happens if I dose 2-part into freshly mixed water (before a water change)?

[LivinTheSwreefLife]

Hi, this may be a really stupid question so I apologize in advance if it is. But, if I'm changing 10% of water on my small tank, and am trying to keep parameters as stable as possible for SPS corals, would I be able to add 2-part to bring up calcium and alkalinity in a bucket of freshly mixed saltwater?

 

[PapaDragon]

The only reason I can see doing this is if your salt mix was way below what's in your tank, but most salt mixes are pretty good about getting the parameters right.

 

[Randy Holmes-Farley]

I agree. Salt mixes often have higher alkalinity and sometimes higher calcium than reef aquaria, so such a thing should rarely be useful, but it certainly can be done.

However, you should not use a water change as a delivery method of even more calcium and alkalinity because too high of alk in the salt water will cause precipitation of calcium carbonate.

 

[joeyhatch11]

Using red sea vs red sea coral pro the difference in mag is rather big. I keep my tank at a 1400 where the new mix will come in at a 1260. Alk and calcium are fine at 9 and 400. But i do add 100ml to a 5g bucket to bring it to 1400.

 

[Randy Holmes-Farley]

Using red sea vs red sea coral pro the difference in mag is rather big. I keep my tank at a 1400 where the new mix will come in at a 1260. Alk and calcium are fine at 9 and 400. But i do add 100ml to a 5g bucket to bring it to 1400.

It is certainly fine to add magnesium to a salt mix. I did that for many years because Io used to be low on magnesium (it no longer is). I also used to boost calcium for the same reason.

 

[Waters]

Randy, what do you consider low magnesium in regards to IO? I currently use IO Reef Crystals and still have to add Magnesium since it mixes up to around 1290......maybe I am elevating magnesium when I don't need to (I keep my tank at about 1380)?

 

[Randy Holmes-Farley]

Randy, what do you consider low magnesium in regards to IO? I currently use IO Reef Crystals and still have to add Magnesium since it mixes up to around 1290......maybe I am elevating magnesium when I don't need to (I keep my tank at about 1380)?

That's certainly lower than their manufacturing target level for 35 ppt seawater.

What salinity are you getting that value at?

 

[FlyinBryan]

I do..for me lately..my freshly made water.. regardless of brand..has been testing very low on all the mjr elements even at 1.025, yes the most popular and well touted are all coming out deficient lately especially Mg, without this you can't hold higher alk/calc. Id test new water before putting in and make sure they match closely.

 

[Waters]

1.025 using a Milwaukee digital meter. I just recently started dosing because my Mg was continuously below 1300 so I tested my newly made water which was testing around 1280-1290 using Salifert tests.

 

[Randy Holmes-Farley]

I do..for me lately..my freshly made water.. regardless of brand..has been testing very low on all the mjr elements even at 1.025, yes the most popular and well touted are all coming out deficient lately especially Mg, without this you can't hold higher alk/calc. Id test new water before putting in and make sure they match closely.

It should be low at sg = 1.025.

At 35 ppt (sg = 1.0264) everything will be about 5.6% higher (except pH and ORP).

So magnesium at 1250 ppm (at sg = 1.025) becomes 1320 ppm.

 

[Waters]

So based on that information, what is the proper magnesium level for a reef at 1.025 sg? Is the 1280 that I am testing at ok or should I be dosing (like I am currently doing) to bring it up?

 

[Randy Holmes-Farley]

So based on that information, what is the proper magnesium level for a reef at 1.025 sg? Is the 1280 that I am testing at ok or should I be dosing (like I am currently doing) to bring it up?

Proper is an opinion question, but natural seawater at a sg of 1.025 will have a magnesium level of about 1212 ppm. I wouldn't keep a reef there, however. I'd target 1250-1350 ppm in most cases.

 

[Waters]

Ok....I may be a little on the high side then.....I have been targeting roughly 1380. If it provides me no benefits, then I may as well save some money. Thanks Randy.

 

[Randy Holmes-Farley]

Ok....I may be a little on the high side then.....I have been targeting roughly 1380. If it provides me no benefits, then I may as well save some money. Thanks Randy.

Higher than normal magnesium may have benefits (perhaps less precipitation of calcium carbonate on pumps, perhaps faster coralline growth), but there's not strong evidence of exactly how much of a mag boost brings what benefits.

 

[MikeDesjean]

Higher than normal magnesium may have benefits (perhaps less precipitation of calcium carbonate on pumps, perhaps faster coralline growth), but there's not strong evidence of exactly how much of a mag boost brings what benefits.

I am was using Reef Crystal and switch to IO a while back and calcium has been falling ever since and I was dosing all for reef as well. but over time is gone down. right now I am at 8.5 alk and 380-400 ca.

If I slowly dose up to my desired target of 9.5 alk and 450 ca, should I start to dose the fresh salt water which is IO to reach the desired parameters? I just picked up B Ionic and may consider switch to ESV salt as well as it is close to where I want to be.

Hopefully I can get some help on this older thread lol!

 

[Randy Holmes-Farley]

I am was using Reef Crystal and switch to IO a while back and calcium has been falling ever since and I was dosing all for reef as well. but over time is gone down. right now I am at 8.5 alk and 380-400 ca.

If I slowly dose up to my desired target of 9.5 alk and 450 ca, should I start to dose the fresh salt water which is IO to reach the desired parameters? I just picked up B Ionic and may consider switch to ESV salt as well as it is close to where I want to be.

Hopefully I can get some help on this older thread lol!

Since high alk salt mixes are prone to precipitation of calcium carbonate, you risk spurring more if you boost the calcium in the new salt water substantially, and I'd just add it to the tank. But you could just boost the calcium in it and take some risk. I would not boost alk in it. It is already higher than your target, unless a lot has already precipitated, and alk is a bigger driver of precipitation.

 

[MikeDesjean]

Since high alk salt mixes are prone to precipitation of calcium carbonate, you risk spurring more if you boost the calcium in the new salt water substantially, and I'd just add it to the tank. But you could just boost the calcium in it and take some risk. I would not boost alk in it. It is already higher than your target, unless a lot has already precipitated, and alk is a bigger driver of precipitation.

If I were to dose tank to my parameters wouldn’t I just end up in the same boat when after a while with 10% / 20% h2o changes with salt mix that is not even close to calc level? Target 450/ IO mixes at 380ish.

would you advise just getting into a salt like esv that has pretty much exactly what I am looong for in terms of parameters. 9kh/450 ca/ 1380 mag?

 

[Randy Holmes-Farley]

If I were to dose tank to my parameters wouldn’t I just end up in the same boat when after a while with 10% / 20% h2o changes with salt mix that is not even close to calc level? Target 450/ IO mixes at 380ish.

would you advise just getting into a salt like esv that has pretty much exactly what I am looong for in terms of parameters. 9kh/450 ca/ 1380 mag?

There's no inherent reason a salt mix needs to match tank unless you plan to do large water changes, but if you want it to do so, that can ease the dosing issues.

It is important to note that 11 dKH and 450 ppm calcium is much more likely to precipitate calcium carboante in the raw salt water than in an aquarium at the same parameters due to all of the things in an aquarium that serve to reduce precipitation onto calcium carbonate surfaces (phospahte4, organics, even whole bacteria that all coat these surfaces).

You can also lower the alk in the IO if you want it lower and calcium higher.