How Exactly Do I Perform Water Changes?

aztec reef

Active Member
old salt bucket, a hose to syphon water,a powerhead to aerate new salt mix,a heater,a pump/powerhead to pump the new water form bucket to tank.
 

lion_crazz

Active Member
When I do a water change, here is my process.
I have 2 trash cans. A good water bucket, and a bad water bucket. The two are never mixed. I have "good" on one, and "bad" on the other. Since I do 40 gallon water changes, I use a 45 gallon trash can.
Fill up a trash can with water. Pour the salt in. Guess-timate it the first time. Put a heater in, and heat it to the exact temperature of the tank. For the first 24 hours, put a powerhead on the bottom of the bucket/trash can to mix the water with the salt. Salt will fall to the bottom, so this is where you want your powerhead. After 24 hours has passed, bring the powerhead closer to the top to increase the oxygen. Dissolving salt with water uses the oxygen up in the water, so you need to replace this. You could use an airstone, but I just use a venturi powerhead because it sucks air in (I run 2 poweheads, one at the top, and one at the bottom, since I have such a huge trash can - you only need one). After the first 24 hours has passed, check the salinity and pH and adjust accordingly. If it is too high, add regular water. If it is too slow, add more salt. If your pH is different from your tank, check your alkalinity. Many times, you need to buffer alkalinity because there are some salts that you give a low alk level.
Once the salinity, pH, kH, and temp are EXACT to your tank, you are ready to do a water change.
When I do a water change, I never dump water into the tank. I have a 5 gallon bucket that I use to take water from my trash can. I put the five gallon bucket on the floor and pump water from the 5 gallon bucket to my sump using a small powerhead and some tubing. This way, the fish are not getting stressed out by you adding a lot of water to the top of the tank. They do not even realize that you are adding water to the tank because it is calm, plus all the water levels are identical to that of the tank. (Plus, this way is a lot less messy).
 

earlybird

Active Member
Almost exactly like lion crazz,
Originally Posted by mrdc
Just thought I would drop a few words about how I do a water change in hopes in may help the new people and if I am doing something wrong, I will ALWAYS take some helpful advice.
1) Decide on how frequent you want to do water changes so you can decide how much water to change at a time. I do a weekly 10% on a 120g tank. Some people do weekly, bi-weekly, monthly, ... and never (not suggested). I mentioned time and % because I look it as you should change more water as time passes. For example, if I did monthly changes I may do 15%. I don't have a formula but I wouldn't want to do say a 40% water change a month to compensate for 10% weekly water changes. It also depends on how much you feed, things dieing, ... and checking your water paramters. Sometimes, intermediate water changes outside your schedule are needed. Basically there is no clear agreement on how often or much to do water channges. However, large water changes should only be needed when something is going wrong.
2) I also really don't want to get into the whole RO / tap water argument (even though I use RO water) so basically fill your container (use a dedicated container) with water (I use an 18g dedicated plastic container).
3) Add a powerhead that is sufficient enough to circulate the entire container and a heater set at a temp to match your tank's temp.
4) Slowly add the salt. I know how many scoops my changes need and I like to add 1/4 of the amount needed slowly and then let it circulate for about ten minutes. After that, some of the salt sits at the bottom which I will pick the power head up and manually blow it around. I wait another 5 minutes or so and then add another 1/4 and repeat the process until 100% of the salt is added.
5) Even though I know how much salt I usually need, not every scoop is perfect so I still use my refractometer which I reccommend. I also calibrate it every few weeks. If you use a plastic hydrometer then I guess use it.
6) Once the salt has been added and I can see no settling, I test the salinity and if it's slightly low or high (and I mean slightly) I leave it.
7) I let it circulate for roughly 22 hours. I then test the temp and salinity and if either is off I fix it over the next 2 hours. Temp is easy to fix and is self explanatory and I don't worry about a degree or 2. If the salinity is low (which should only be slightly if you followed step 6 and left the "off" as slightly), I add a little salt and check periodically. I add more if needed which usually isn't needed. If it's high, I slowly add some more RO water.
8) After everything is in place (salinity and temp in normal parameters), I let it circulate for about another hour and then do my water change.
9) I have another 18g dedicated container for the old water.
Side notes:
1) I believe in having dedicated containers, one for water change and one for old water and those containers are ONLY used for the purpose of water changes.
2) I replace evaporated water ONLY with fresh RO water and nothing else. If your salinity is off in your main tank, I would correct the problem but either adding water with salt or taking away some water and replacing it with water with no salt before I do a water change. I would do it this way and not by trying to correcting it cia water change and I would correct either way very slowly. So if your salinity is off by A LOT for some reason, don't start adding a bunch of salt and try correcting it in 5 minutes. That will shock your tank and may have bad consequences.
3) Get a refractometer. I won't argue about the RO / tap water or which salt to use but if you want accuracy, IMO a refractometer is a must. And don't leave it in the garage if it gets hot in your area because the plastic cover over the reading area will warp! Also, calibrate it with the right water or other solution.
Well that's it for now and I hope that I may help someone because my first water change came with questions. I may add more later and if anyone has more to add, go for it.
Thanks for reading.
 

aztec reef

Active Member
nice! lion, i do the samething except i use 2 5g salt buckets and i also use two powerheads to aerate the new water, i get clear salt water in about five minutes(looks like fresh ro) but i still let it be for 24hrs before change.
 

aztec reef

Active Member
is an easy to read device and more accurate than a hydrometer,they read in percents and specific gravity. easy- just add a few drops to refractometer and read
 

feathers212

Member
I usually mix 1/2 cup of salt per gallon of RO water. I keep the mixture circulating for about 24 hours, using an airstone to add oxygen. Gives me specific gravity of 1.024-1.025.
And the refractometer is the best to go.....much more accurate than the hydrometer and worth the investment.
 
Cool! Thanks for the advice...it looks like I have to get together quite a bit more equipment prior to making my first water change.
 

larryndana

Active Member
Originally Posted by fishwanabe
sorry to jump in but, I plan to have a 90g how much of an h20 change and how often do I need to do it?
15 to 20 percent every other week. for a 90 thats 13.5 to 18 gallons, i'd do a nice round number, lol, 15 gallons.
 

fishwanabe

Member
Thanks larrydana- sorry they took your signature *fish swimming* smiley away..I got used to it after each one of you post.
 

fish addict

Member
You're from Nebraska?? Rock on! There is no one from Nebraska I swear I think you are the first person I have seen on here from NE! Woot Woot! lol
 

larryndana

Active Member
Originally Posted by fishwanabe
Thanks larrydana- sorry they took your signature *fish swimming* smiley away..I got used to it after each one of you post.
i don't remember using it that often but, well this one is a little different.
 

prevwon

Member
If you use a Powerhead to add oxygen, do you put it at the very top of the water, to where it's almost out or do you put it a couple of inches under the surface?
 

fish addict

Member
Originally Posted by HuskerReefer
Yup...Bellevue, NE. Where are you from?
Geneva NE, fun stuff! Used to live in CO but that was b4 I got into SWF. I have to drive an hour to get to a fish store and they hardly ever have anything at fish stores around here it seems like! And there is only one other person in all of geneva that has a fish tank, my Cross Country coach. You can imagine how surprised I was to find out he was into SWF!
 

beaner

New Member
(Qoute from lion fish)For the first 24 hours, put a powerhead on the bottom of the bucket/trash can to mix the water with the salt. Salt will fall to the bottom, so this is where you want your powerhead. After 24 hours has passed, bring the powerhead closer to the top to increase the oxygen. Dissolving salt with water uses the oxygen up in the water, so you need to replace this.
I believe this is the answer you were looking for
 

walkerbrody

Member
I use a 10gal container plumed into my system. This container gets about 10 gph to make water changes gradual. I turn 2 valves to bypass the container, empty the container, fill it with ro water and salt, use a powerhead to stir for 24hrs, then turn the valves to return it to the system. It works easily for me. I was wondering if it might cause any problems I do not know about.
 
Top