Increase Salinity

I have a 150 gallon FOWLR and the salinity is at 1.0215 (around total volume of 135 gallons after rock and sand). I want to get it up to 1.024. I ready I can just top off with salt water, but that seams it will take a while.

I can also do water changes with the desired salt level or higher. What is the max that I should raise it with a water change. For example, if I want to change 25% of water (around 30 gallons), with the current water at 1.0215, if I remove around 30 gallons and add in 30 gallons at 1.0270, the increase should be to around 1.0227. Is 0.0012 Change to much or could I actually do more and be safe such as have an increase of 0.0015 to go from 1.0215 to 1.023 in one water change?

thanks,

Mike
 
If there are fish or corals, you can topoff, as you know, with salt water. You can also supersaturate the water you are using for topoff, with a mixing pump. Just don't overdo it. Creatures tolerate a rapid lowering of salinity pretty well; but a rapid INCREASE can rupture organ tissues and kill, not necessarily immediately, but due to organ failure. Kidneys are particularly vulnerable, so IME fish tend to suffer more than corals do.
 
Do u have fish in the tank or anything else right now? If no then I would just take some water out and raise it up to where u want it in one shot. If yes then I would do it a bit slower bust it up over a few days. I keep my tank at 1.026. To get your SG up you will have to over shoot by a few numbers. I've done this with a 10% water change before. Also if u get close lets say 1.023 or 1.0235 then u could just not top off and the SG will go up by it self.
 
If everything looks ok now, don't worry about it. Just mix up your next batch of saltwater to the proper level, and over time things will balance themselves out. IME, salinity doesn't necessarily have to be spot on. These corals are a lot more durable than one might think. Just as an example, those plastic swing arm hydrometers are notoriously inaccurate, yet there's a lot of hobbyists out there that use them & still have beautiful reef tanks. JMO, GL.
 
i have in the past added salt directly to the sump of my 180g sps reef with no ill effects, but never more than 3-4 cups. i should also note that i have a 75g sump.
 
I use mixed salt water at higher sg up to around 1.035 to raise aquarium sg., limiting increases to 0.001 per day to insure against osmotic shock.
Fish including marine fish have a natural internal sg of around 1.008. They must maintain that internal sg to avoid a loss of homeostasis and the proper fuctioning of their internal chemistry and organs. Marine fish have evolved to thrive in 1.0264 sg on average. They drink a lot and pee a little excreting urea packed with concentrated salts and wastes to stay hydrated. Raising sg too fast stresses them ,they need time to adjust to keep up..

Corals and invertebrates are different they can't osmoregulate like fish can and need the water outside them to be close to their internal sg around 1.0264. The op has a fish only tank.
 
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thanks. I do have fish. The tank has been running for around 5 years. I am just going to top off with salt water.

thanks,

Mike
 
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