Specific gravity issues :/

Mike1995

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So the salinity in my tank is at 1.015 or so. I tested with a refractometer. I've been trying to increase it with top offs with 1.028. it was at 1.010 before. it's slowly increasing. Would it be easier to just do a good size water change and put water back in with correct SG? I kinda didn't know what I was doing the first time around.
 
A combination of both isn’t bad.
Just don’t go to large a water change. Like 5 gal in a 55 isn’t bad.
 
I have a 75g .so would like 10 gallons be okay?
Yes. Also, If you blow a fan at the tank it will evaporate much faster. With salt water top off and a fan it should raise salinity quickly. Just don’t go too fast I would limit the increase to 0.005 per day.
 
If I do a lot of fragging or selling, you very quickly can hit a lower salinity due to using water for dipping, rinsing, transporting corals in cups, etc etc. I learned the lesson to pre-mix a couple gallons of water to top off my tank ahead of time, as I'll use a gallon or two. But previously, I'd note my water was down to like 1.023 -- not ideal, so I'd top off with a couple gallons of freshly mixed salt water. As it evaporates it safely raises the tank SG.

It's what I recommend to people, simple, effective, and slow.
 
Did you calibrate your refractometer with 35ppt (1.026) calibration fluid before testing? Mine is often out of calibration when I get it out of the case.
 
Did you calibrate your refractometer with 35ppt (1.026) calibration fluid before testing? Mine is often out of calibration when I get it out of the case.
Is that different than saltwater? If so I don't have any . I didn't know I had to use that . The only thing I've been doing is turning a little screw on top of the refractometer to zero it
 
Is there any livestock in the tank? if so you want to increase it really slow. If no, then you can do a large water change with the correct or slightly higher SG or just add salt directly to the tank to raise it.

Also, if i add it to the tank, will it dissolve by itself?, I do have a lot of flow, will that help? I did this before and it made the water really cloudy
 
Is that different than saltwater? If so I don't have any . I didn't know I had to use that . The only thing I've been doing is turning a little screw on top of the refractometer to zero it

You ideally want to use calibration solution that is 35 ppt. You can buy or make your own. I talk about it in THIS ARTICLE.
 
I agree with just doing the top offs with saltwater. Essentially with your present salinity, it is ~hypo salinity which is not a terrible thing. A drastic sudden increase could be detrimental to the inverts you mentioned unless you wish to remove what little livestock is in the tank, increase it at one time and then drip acclimate the critters before reintroducing.
 
I'd first calibrate your refractometer before doing anything else. If you don't have a salinity standard, I would order or make one. They're cheap enough. In the meantime, freshwater will suffice, even though it's not always the most accurate. Clean and dry the refractometer well and put a few drops of deionized water on the slide. Verify that the reading is zero. If it isn't, adjust it.

If your reading is accurate and your salinity is as low as 1.015 sg (or 20 ppt), I would do both saltwater topoffs and water changes. 20 ppt is way low for saltwater aquariums. Just go slow. I would shoot for one ppt of increase per day.

To determine how much of a water change you need to do, subtract 35 ppt (the salinity you should target) from your tank's current salinity. Multiply that number by the percentage of the change to get an idea of how much salinity will increase. So for instance, if your new water is 35 ppt, subtract 20 ppt (what your tank currently is) from that, and you get 15 ppt. A 10% change would increase your salinity by about 1.5 ppt (15 ppt * 0.10 change). So I'd shoot for under a 10% daily change until your salinity gets a bit higher.
 
So... I calibrated my refractometer correctly... Eh it's 1.037. so it's actually to high... Sorry for wasting everyones time lol. To lower it do I just put freshwater in the tank?
 
With snails and hermits, they are surviving in 1.037 already so keep adding fresh. I had a similar problem almost 2 years ago and my salinity was right around your number. I had snails, hermits, clown fish, damsels, a toadstool, a brain and zoas. A few of the damsels died from the high sg though. When I realized it was that high I brought it down to 1.026 overnight and everything survived just fine and are all still living today. I am always comfortable bringing sg down fast but going up verrry slow.

BTW you did not waste anyone's time. Members still posted helpful information that may be useful to others.
 
So... I calibrated my refractometer correctly... Eh it's 1.037. so it's actually to high... Sorry for wasting everyones time lol. To lower it do I just put freshwater in the tank?

It's never a waste of time. We're all here to help each other if possible.
 
Would it be easier to just do a good size water change and put water back in with correct SG?

I wouldn't sweat it. Regular water changes at the correct SG will eventually get you where you want to be. Be patient.
 
@Mike1995 you first reported a low salinity...then recalibrated to calibration fluid....and now report a very high salinity at SG of 1.036. That is very high....48 ppt (note 1.026 sg is 35 ppt). I'd highly recommend having a fellow reefer test your salinity or take a sample to your LFS and have them test.
 

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