Few ? about Hypo

[bsktmom]

I'm getting ready to do hypo on my fish and I have a few questions. I just set up my hospital tank last night and used water from my display tank. I am going to tests both tanks but if there is a slight difference in tests should I acclimate the fish to the new tank? I know it says over a 48 hour period bring the SG down to 1.009 or 14 pt. salinity. What is a safe way to do this? I know that I will be replacing regular water with salt water but how much how often? Thanks for the info. I may have a few questions later but this is all for now.

 

[elfdoctors]

Your fish should have an acclimation (to adjust for differences in temperature, salinity, and other chemistries (e.g. display tanks, especially reefs, tend to use up more calcium and carbonates then quarantine tanks). Assuming you used water from your display tank, this can be done quickly (<1 hour). Try to make sure your hospital tank water has the same or slightly lower salinity.
There are lots of ways to bring the salinity down. There is no right way as long the salinity drops gradually.
If you are using an uncycled tank be prepared for lots of water changes.
When I have done hypo I would start by mixing up a large batch of 1.009 water. I would then do a 20% water change by taking out the water quickly then every 1/2 hour I would add back ~1/5 of the water. When you get closer ~specific gravity 1.014 (~4-5th water change depending on your starting salinity) I would start by adding aged freshwater. Let the fish rest for a few hours before starting the next cycle.
An alternative would be to use just freshwater but to use a smaller amount of change (e.g. 10%) for the first 4-5 water changes. I would tend to recommend this method if your tank has already cycled.
Make sure you watch your ammonia, nitrites and pH. As long as these stay under control, hyposalinity is very safe.

 

[jwhiteuwc]

Elfdoctors,
You've brought down your tank to 1.009 in less then 24 hours?
Not that I'm saying you're wrong in doing so, just curious as I'm in the process if HYPOing another tank right now .

 

[beth]

There is a post on hyposalinity in the FAQ Thread which details the procedure. Getting the salinity down over a 24 hr period is the best way to do it, but you can step it up. Lack of fish stress resulting from lowering the salinity needs to be your judge for how fast to make the drop. It is best to do this in smaller rather than larger increments. You can removed several gals at a time, then over the course of several hrs or a day, begin replacing the water with fresh buffered RO water.

 

[jwhiteuwc]

Wow, I thought I read you should do it over a 48 hour period and not 24.
From a website:
"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]

Originally posted by jwhiteuwc
Elfdoctors,
You've brought down your tank to 1.009 in less then 24 hours?
Not that I'm saying you're wrong in doing so, just curious as I'm in the process if HYPOing another tank right now .
I never said this. I actually took longer than 48 hours the first time I did hypo as I did not have a refractometer yet.
I pointed out in my post that I let the fish rest for a few hours after each change. I would only do 2-4 changes a day depending on my availability at home. I would often have to remove the water and then ask my wife to add the water back setting an alarm every half hour.
The approach I described is a way to gradually drop the salinity. I also used 1.009 water to begin with so the salinity didn't drop as much early on.
Sorry for any confusion.

 

[jwhiteuwc]

I didn't think you did. Just wanted clarrification in case someone else misread your reply like i did
Never doudted you.