First time at Hyposalinity

revfred

Member
Let me first of all say that I've been in the hobby for only about 1 year. I experienced several losses last year and almost gave up. However, I feel like Al Paccino in Godfather 3 "Every time that I try to get out, they keep pulling me back."
I have a Rock Beauty Angel and a Royal Gamma that are showing signs of Ick. They have small white spots on them that look like salt. I'm going for the hyposalinity as opposed to quarantine because I have a fish only display and I'd rather treat all of my fish (I also have a yellow-eyed tang and 3 damsels).
AM I DOING THIS RIGHT? I am going to replace the tank water with unsalted water in 5 gallon increments every 4 hours until I reach the desired salinity level. I am measuring my salinity along the way with a floating hydrometer.
Am I on the right track?
 

elfdoctors

Active Member
That sounds about right.
It may take you a while to get down to 1.009 doing it that way. I actually calculated that it would take 21 water changes that size to go from a specific gravity of 1.025 to 1.009. That would take 84 hours which is acceptable. If you don't plan to wake up in the middle of the night, I would consider doing 10 gallon water changes but adding the unsalted water back gradually (perhaps 2 gallons every fifteen minutes) to minimize osmotic shock.
You can do hyposalinity with a large lab grade hydrometer but I would strongly recommend looking into a refractometer.
Good Luck and welcome to the boards!
 

guitarfish

Member
I think you're in for a huge amount of work doing hypo in that large tank. If you're going to be in the hobby for the long haul, why not get a 20g or 30g to use for the hypo, and for subsequent QT when adding new fish?
Don't forget all the salt you eliminate, you'll need to add back. That's an expense to consider in a big tank too.
 

revfred

Member
I do have a 20g set up for a QT. However, I have my Rock Beauty showing signs (who is about 6" long), my Royal Gamma, and my Yellow-eyed Tang now showing signs. I figured that the 20g might be a little small but after a few water changes that I've done so far and seeing little changes, I may do the QT instead.
 

elfdoctors

Active Member
It definitely is safer for the fish to do hypo in the larger tank. That many fish (with at least one 6 inch one) will probably put too much strain on the 20 gallon. The higher fish density will make it harder to regulate the pH (because you lose a lot of the buffers when the salinity drops). You would probably have to do more water changes during the three weeks in hypo in the smaller tank as your fish will be at risk during that time because of overstocking.
You probably underestimated how many 5 gallon water changes had to be done to get the salinity down. Larger water changes would get the job done with less work. Use the smaller sized water changes when you bring the salinity back up - that phase has to be done slower.
Perhaps use the 20 gallon for your inverts, live rock or corals (if any).
 

guitarfish

Member
I agree it's safer to use a larger tank since he has 6 fish. A 40g may be a better QT solution. Doing hypo in a 110...wow that's gonna be a lot of water.
 

guitarfish

Member
As regards diluting the water down to 1.009, here's a little formula I came across from Andrew Trevor Jones:
"Your starting point should be between 1.025 and 1.027. Replace about one fifth of the volume with RO, RO/DI or aged freshwater that has been well aerated. Repeat this 12, 24 and 36 hours later, monitoring the specific gravity along the way. After the fourth water change the specific gravity should be 1.010 or pretty close. Wait a few hours to make the final adjustment to get down to 1.009. Note that you can estimate the resulting specific gravity. If you are changing one fifth of the water and the current specific gravity is 1.025 the result will be:
((1.025*4)+1.000)/5 = 1.020 approx.
Then, after 12 hours:
((1.020*4)+1.000)/5 = 1.016 approx.
After 24 hours:
((1.016*4)+1.000)/5 = 1.013 approx.
After the 4th change:
((1.013*4)+1.000)/5 = 1.010 approx. "
 

elfdoctors

Active Member
Who is Andrew Trevor Jones?
A variation of that formula is what I used to calculate 21 water changes using only 5 gallons per change which is what RevFred was originally suggesting.
The technique guitarfish suggested would certainly involve less work. My only concern about those relatively large fluctuations would be subjecting the fish to osmotic shock. The freshwater should probably be added gradually to minimize this risk.
 
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