Need to raise salinity, what else will the affect?

[Pennywise the Clown]

For a year, using my Red Sea refractometer, I measured my salinity at 1.024. As I bought my water from my lfs I let it sit at this level and everything seemed to be doing okay.
I have just purchased a Hanna salinity tester (which I absolutely love) and it turns out that my salinity is actually 1.022.
Better late than never, I am now going to mix my own salt water and slowly raise my salinity to 1.026. I will do this by my weekly 10% water changes.
Will this raise in salinity affect my dkh, calcium and magnesium levels?
And if so, how will it affect them?

Thanks.

 

[W1ngz]

Everything will go up proportionally.

You can also gradually increase your salinity by using salt water for your topoff water temporarily, until you get to the salinity you want to keep.

 

[homer1475]

As above, instead of large jumps while doing a WC, just put salt water in your topoff. Just measure daily until you get to where you want, then switch back to fresh.

As you increase salinity with any salt mix, you increase the elements in the water. More mix = more elements(ALK, Cal, MG, and everything else in the mix).

 

[Bayareareefer18]

Agree with the others. I had the same issue with my refracto reading off. I hadn't realized it even though I calibrate occasionally.

As the others stated I just swapped the RO for SW in my ATO res and that did the trick

I now use the hannah as well for salinity

 

[DeputyDog95]

Let's say your salinity was 1.029 and your magnesium was 1400.

And then you lowered your salinity to 1.026 in the same day. Hypothetically, I know that's a bad idea.

What should the magnesium level be now at the lower salinity? Is there a way to calculate that?

The reason I'm asking is that I did inadvertently run my tank at about 1.029 and I'm slowly lowering the salinity a little every day. However, what I'm finding is that my dosing routine has gone up significantly and I'm wondering how much of this is the corals being happy again and therefore using more, and how much of this is that the elements are lower in my tank now as the salinity is shifting down and the dosing is increasing to get back to targeted values.

Any thoughts?

 

[Randy Holmes-Farley Verified Community Expert]

The magnesium goes to 26/29 x 1400 = 1255 ppm

 

[DeputyDog95]

The magnesium goes to 26/29 x 1400

The magnesium goes to 26/29 x 1400 = 1255 ppm

Is that a standard formula that can be applied to alkalinity and calcium too, Randy?

Seems way too simple and I don't really know why that formula works, but I never would have come up with that

 

[DeputyDog95]

Oh wait, I see what you did there. Simply came up with the percentage difference and applied it. Duh. I'm tired and math is hard LoL

 

[Randy Holmes-Farley Verified Community Expert]

Is that a standard formula that can be applied to alkalinity and calcium too, Randy?

Seems way too simple and I don't really know why that formula works, but I never would have come up with that

Yes, it applies to everything except a few rare exceptions such as pH and ORP.

 

[DeputyDog95]

Yes, it applies to everything except a few rare exceptions such as pH and ORP.

Thank you. Very interesting as I wasn't expecting my main three elements to be moving down so much with such small changes. I've only changed out 5 gallons with RODI (1 gallon Sat, then 2 gallons Sun, then 2 gallons Mon) since Sat (net 120 system), and it's lowered from 35.1ppt to 33.7ppt. Relatively small adjustment, by design.

I have my Trident managing the Alk, but I'm upping the Ca dosing and adding Mg manually to keep it all balanced and target my previous stable readings (8.5, 450, 1400).

Yet one more reason to do this rather slowly...

Aside from changing the salinity and letting the corals adjust to the change, doing this over a week or so allows you to adjust your main three parameters to hold as close to steady as possible with your Alk, Ca, and Mg during the transition up or down. Which I'm sure the corals appreciate, especially SPS.

As it stands now, with Alk alone, I went from around 55ml per day to over 70ml per day and I'm still not maintaining my target dkh yet (8.5), but it's close at 8.3dkh.

I think I'm going to go every other day from here so I can let the salinity drop a little, and then adjust my Alk, Ca, and Mg to meet my target numbers before dropping it again.

On a side and related note...

My corals were growing and had good PE, but the colors were really starting to fade some. Not browning out, but I have dozens and dozens of colorful SPS frags and small colonies and many were losing their "pop". I'm seeing color starting to rush back in already, which is really encouraging that I'm doing the right thing. In particular, I have a mini infidel colony which at one point had a very cool almost purple/blue appearance with orange polyps. It slowly faded out to a pale blue and the polyps lost their orange for the most part. The tips are almost electric again, which I'm really excited about. I have an encrusted Jolt frag that started out with a million colors and has really faded. No significant change their yet but I'm hopeful and think I'm on the right track.

Thanks again!

 

[Hans-Werner]

The magnesium goes to 26/29 x 1400 = 1255 ppm

I am a bit surprised it works also. I would have calculated:

1.0264 = 35 PSU
1.0294 = 39 PSU
35/39 x 1400 = 1256.4, different way, same result.

 

[Smoke-Town]

I've heard mixed reviews on Hanna digital refractometer accuracy... there are a few videos on youtube where a guy buys 2 and calibrated them and they both show different results on his tank.

Could try calibrating the refractometer with rodi water to make sure it's reading 0.

But regardless of which one is telling the truth, 1.022 or 1.024, raising the sg by .02 is the way to start

 

[DeputyDog95]

I've heard mixed reviews on Hanna digital refractometer accuracy... there are a few videos on youtube where a guy buys 2 and calibrated them and they both show different results on his tank.

Could try calibrating the refractometer with rodi water to make sure it's reading 0.

But regardless of which one is telling the truth, 1.022 or 1.024, raising the sg by .02 is the way to start

My LFS had a Hanna too. We put them in the same tank at the same time... Mine read low by .002 and theirs read .003 low as compared to both of our calibrated refractometers.

They did say their Hanna is "consistently" wrong, so they keep using it. Hanna asked for them to send it back, but they declined since it's a "known value" now and usable so long as you make the mental adjustment and they were afraid it might come back and be inconsistent.

I went ahead and put a label on mine for "1.024" so I don't forget that is reads low. For now, I'm going to use my Milwaukee and the refractometer to make my water, and test the Hanna a few more times to make sure it lines up to my actual 1.026 at the Hanna's displayed 1.024.

Right now I just don't trust the Hanna enough to just roll with it after juicing my tank up to almost 1.030.

Trying to get the tank back down is a slow and tedious process if done correctly. It's not hard, but you have to daily small salt water removals with RODI replacements, and then adjust your dosing immediately to accommodate. It's getting there and hasn't balanced out, but I'm getting closer! Slow and steady is the name of the game with SPS

 

[gbru316]

How do you know the Hanna is accurate? Have you tested it? Have you tested your refractometer? If you haven't tested either, you don't really know which one is more accurate. You're confusing "different" with "better."


Personally, I wouldn't make any changes until I've confirmed the accuracy of one of the devices. ESPECIALLY if your tank is doing well.

 

[DeputyDog95]

How do you know the Hanna is accurate? Have you tested it? Have you tested your refractometer? If you haven't tested either, you don't really know which one is more accurate. You're confusing "different" with "better."


Personally, I wouldn't make any changes until I've confirmed the accuracy of one of the devices. ESPECIALLY if your tank is doing well.

I do water changes every other week, my maintenance guy does the alternate weeks or when I'm traveling. It all started when I got the water to what should have been 33ppt on his days, and I asked him to finish it off to get it adjusted to 35 before the service. He got 37 on his refrac, twice in a row.

Got me curious. Then I decided to open a box with a BRS refrac with reference solution after it had been for a while and I came up with tank water at 38-39. Now I'm concerned...

Shortly after, i got some specimens from Jason Fox and tested his water for grins and it was coming in at around 31-32. I don't think the salinity should change much with shipping, so I knew something was wrong.

From there, I went to my two local LFS and confirmed the Hanna was wrong and that my Milwaukee and Refrac were lining up with both the BRS reference solution and their own store tank readings. My Hanna was reading well below the expected numbers at both LFS's.

So I feel pretty confident at this point. The only thing I noticed was that growth was a little slower with some species than should be expected, and the coloration was not as good as it should with a lot of the SPS. 38-39 was probably just high enough to irritate but not kill stuff. At least over the period of time I've been using the Hanna. Probably 6 months.

I'm down to 36ppt after 6 days, so far so good. I've been able to keep the Alk steady at 8.5dkh, but it's been a bit of a chore to keep the dosing correct for Alk, Ca, and Mg as they lower as the salinity lower and you have to adjust up.

Things are for sure out of balance at the moment as my Red Sea "A&B" should be 3 Alk to 1 Ca, and the Ca ratio is much higher than it should be at the moment. I'm sure it will take a while to get it to balance out, but it was perfectly balanced with a 3 to 1 prior to this.

Lessons learned. Now I just need to patient and keep adjusting down to 35ppt and waching the numbers and adjusting the dosing accordingly.

Appreciate all the feedback!

 

[DeputyDog95]

Just an update on my salinity adjustment.

It took about a week to gradually lower it to my target of 35ppt, but I finally got there. I went ahead and calibrated my Apex salinity probe to the tank water which I now have set at 35. The Apex was still reading 33ppt, because I had previously calibrated the tank to 35ppt using the Hanna, and then calibrated the Apex probe to the Hanna. The Apex now reads between 34.9 and 35.1 ppt, depending on if the ATO has kicked on or not. Which is right on point w the Milwaukee and the refractometer.

Getting the dosing balanced was more of a chore. The tank immediately starting consuming way more Alk and Ca than it had been at the previously salinity. The more the salinity dropped, the more it consumed, as expected.

I'm using the Red Sea liquids, which are a 3 to 1 ratio (the Ca is concentrated. Anyway, it finally balanced back out at my target numbers (8.5 and 450) at the 3 to 1 ration and seems to be steady (knock on wood).

I'm now using about 15% or 20% so more than I had been previously, but during the adjustment period they got as high as 40% from the previous consumption.

I had a pretty regimented feeding and maintenance schedule, with a lot of fish so my nutrients were very consistent (0.04 and 5). They have gone down considerably since the adjustment (0.02 and 3). So I'm still working on that by cutting the chaeto ball in half, and keeping it that size, slowing the skimmer collection down, and adding more aminos.

So far so good! (know on wood)

Appreciate the feedback here!