How to Make a Safe Water Change for Marine Fish

[BigAl07]

You want to mix your salt for at least a day and then TEST the newly mixed salt water. This gives a fairly accurate assessment of your newly mixed salt water. If you test the new salt mix soon after adding your test results aren't accurate at all and you're adding poorly mixed SW to your tank. It's just a good practice to make this a couple of days process.

[naperenterprise]

Lee you should write instruction manuels for a living...lol
Great info! Thanks.

[leebca]

I did, actually. The Dept of Chemistry at Ohio State Univ is still using some of the quantitative chemistry guidelines I wrote for them.

[naperenterprise]

I had a feeling...

Originally Posted by leebca

I did, actually. The Dept of Chemistry at Ohio State Univ is still using some of the quantitative chemistry guidelines I wrote for them.

[dionysusjg]

Hi all.
I'm not sure if I'm just asking for trouble, but I'm not nearly that careful with my water changes.
I usually do a 10% water change (approx 24L at a time).
All I do is fill 2 buckets and mix in the salt.
Wait until the cloudiness disappears (10 mins), re-stir to ensure no salt has settled on the bottom.
I check the salinity and add salt until I'm in the ball-park of my tanks salinity.
I don't check or adjust the temperature of the new water!
I remove the same amount of water from the display tank.
I then use a surgical drip to replace the water over several hours, allowing my heater and chiller to stablise the temperature.

Using this method, I have never had a significant change in either salinity or temperature.

Is there some "pothole" I am not seeing in using this method?

The way I see it, if there is a variation in the salinity of my new water, adding it so slowly will only change the salinity slowly, and the same goes for temperature. By dripping it into the tank, the heater and chiller easily control the change.

cheers

[degibson84]

if i mix my water weeks b4 i am going to use it won't it go stagnent???

[degibson84]

Originally Posted by dionysusjg

Hi all.
I'm not sure if I'm just asking for trouble, but I'm not nearly that careful with my water changes.
I usually do a 10% water change (approx 24L at a time).
All I do is fill 2 buckets and mix in the salt.
Wait until the cloudiness disappears (10 mins), re-stir to ensure no salt has settled on the bottom.
I check the salinity and add salt until I'm in the ball-park of my tanks salinity.
I don't check or adjust the temperature of the new water!
I remove the same amount of water from the display tank.
I then use a surgical drip to replace the water over several hours, allowing my heater and chiller to stablise the temperature.

Using this method, I have never had a significant change in either salinity or temperature.

Is there some "pothole" I am not seeing in using this method?

The way I see it, if there is a variation in the salinity of my new water, adding it so slowly will only change the salinity slowly, and the same goes for temperature. By dripping it into the tank, the heater and chiller easily control the change.

cheers

i have used this method minus the drip for 3 years and never had any problems

[lcstorc]

My water is stored with a circulation pump so it is always moving.
Any differences between the new and old water has the potential for disaster.
IMO the drip does at least slow down the change, but I would still be very concerned about the salt being properly mixed. Most salts have a recommended mixing time to achieve best results. If you mix water and leave it circulating test it every day and see what differences you find.
I always have NSW made up and ready to go just in case.
I have a set-up that makes it easy now but I did the same thing when I was storing water in a trash can, just on a smaller scale.

[leebca]

I will have to review the post and maybe make it clearer. However many people seem to miss the point of this post. Its main purpose is for large water changes. A 10% water change has very little impact on the system in general. That is why, in item 6. I did mention that it was a point where, for a small water change, such controls isn't that important.

There are still some points within this procedure that everyone should follow -- the time for mixing -- for example.

[motocrosstcw]

GREAT POST this should be a sticky for the " New to the hobby " forum. I really injoy reading your post's and take in as much info as possible every time i do a water change i start another one and let it sit under my sink with powerhead running until it is time to do another water change ( Normally about two weeks) Then i read the test and adjust. This is some great info and in fact a must do in my books.

Thomas

[degibson84]

Originally Posted by leebca

I will have to review the post and maybe make it clearer. However many people seem to miss the point of this post. Its main purpose is for large water changes. A 10% water change has very little impact on the system in general. That is why, in item 6. I did mention that it was a point where, for a small water change, such controls isn't that important.

There are still some points within this procedure that everyone should follow -- the time for mixing -- for example.

so if im just doing a 5g change on my 45g it is not going to harm anything???

also how long should i let the water mix for is a few days enough???

[leebca]

If your 45g tank has about 38 gallons in it, then your water change is 5/38 X 100 = 13.2%

You should make sure the specific gravity of the new water is close to that of your tank water, the pH should be close to your tank water, and the temperature of the new water should be up to + 1.5F and -0.0F of the display tank water.

This water change doesn't do well at exporting large quantities of wastes. Water changes of 15% or less per week or every two weeks helps keep the water stable, replenishes some of the micro elements used, and causes the system to reach an eventual equilibrium of ingredients. In a tank with few nitrogen polluters (e.g. a reef tank with few or no fishes), this is a good water change strategy. In a tank that is FOWLR and 'normally' stocked, this can be a bit of a handicap if the hobbyist wants to achieve significant exports of wastes.

What is better for a FOWLR normally stocked system?
15% water change a week or 30% water change every 3 weeks? The 30%.

If you can pereceive why this is, then you're on your way to becoming an effective FOWLR hobbyist. In the case of corals and invertebrates (and systems will few nitrogen polluters), it may be better to do the 15% weekly.

Mix the water for no less than that recommended by the manufacturer but, in no case, any less than 48 hours, aiming for a week.

[newreefguy]

Hmm, it would be a good idea to read instructions on the box, as I didn't either.

[beasone]

Just many thanks for sharing the knowledge and in such an understanding way.

I love the idea of keeping the back up water changes.. guess I will need to invest in a couple more powerheads.

RS is my new bestie!!

[Rhodes19]

Lee, that was a very nice write up and easy to read and understand. I am going to read the insturctions on my bag of salt now and let it mix for at least 48 hours. Thanks.