Water change day !!!???

James Hammett · Apr 23, 2018

Although this chore is necessary it scares me and my students every time we do it. Any tips on how to do a water change with out upsetting everything in the tank? The nems are dong well don't want to cause a crash for them. The corals close and the water gets cloudy after the change for a day or so. Also should we check parameters before the change or after to keep accurate data, or both?

Thanks for your help.

Tahoe61 · Apr 23, 2018

Definitely check and match temp and SG. If water changes are not routine and you have sps and clams then also check alk and calcium.

Your tank should not be cloudy after water changes. The water may appear cloudy immediately post wc, it should resolve within a couple hours. You corals should not be closing up either.

If you have a sump turn off all filtration and perform the water change in the sump. You can also do smaller water changes more frequently.

I change out at least 5 gallons a week and that has been pretty routine for me for years. Make sure your water and salt are completely mixed if you're mixing your own. You can mix it a day ahead of time, and provide some aeration.

James Hammett · Apr 23, 2018

I mix thew water myself let it sit in a bucket with a 450 GPH power head for 4 hour minimum. usually more. I do 5 gallons a week some times every 10 days depending on schedule. I have a 32 gallon Bio cube so cant really do the change in the sump I guess I can add it back to the sum instead of the main chamber. I do make sure the SG is a perfect match to what is in the tank i try to maintain 1.025. The two ZOA frags I have tend to close up and the nems last change completely folded in on them selves causing me to panic and honestly delay this change a bit from a little fear. They are looking great right now.

madweazl · Apr 23, 2018

Does the alkalinity of the mixed water match that of the tank? If not, this could be a likely cause of the reaction you're observing.

Tahoe61 · Apr 23, 2018

What salt mix are you using? Some salts you should mix longer.

Siphon from the front, pour into the back. Break up the water changes by a couple of hours, 2.5 gallons, wait and do the other 2.5 gallons.

Corals will often close up but should open right up. My anemones change shape but return to normal within 30 minutes.

Water changes are your tanks best friend in small tanks, but the room for error is much narrower.

James Hammett · Apr 23, 2018

I am using the same water from the same RODI system so it should match alk.

James Hammett · Apr 23, 2018

I have been using Red Sea just ran out today. I have 5 gallon bucket of Instant ocean that I will start using after this change

K. Steven · Apr 23, 2018

James Hammett said:
I am using the same water from the same RODI system so it should match alk.

No, he means the alkalinity of the tank water and the alkalinity of the newly mixed saltwater.

James Hammett · Apr 23, 2018

ahh SO I SHOULD CHECK ALK IN NEW WATER BEFORE ADDING IT TO TANK

madweazl · Apr 23, 2018

James Hammett said:
ahh SO I SHOULD CHECK ALK IN NEW WATER BEFORE ADDING IT TO TANK

It may or may not be off, just something to check. With Instant Ocean, I usually mix the water for 12+ hours (usually closer to 24hr) and reduce alkalinity (e.g. via muriatic acid) to match that of the tank's water. I also heat the mixed water to match that of the tank. I dont notice any reaction with any of the inhabitants with this procedure.

James Hammett · Apr 23, 2018

I have never considered the temp in water change. Honestly haven't paid attention to result in tank temp either. I have no heater running in my tank just room temp it runs between 77-78.5. I imagine a smaller amount of water in a bucket would be colder

madweazl · Apr 23, 2018

James Hammett said:
I have never considered the temp in water change. Honestly haven't paid attention to result in tank temp either. I have no heater running in my tank just room temp it runs between 77-78.5. I imagine a smaller amount of water in a bucket would be colder

I was seeing a 2.5° delta with a 13% water change so I started heating the newly mixed water. Winter months were a little worse and summer a little better.

James Hammett · Apr 23, 2018

This is why I chose to do this in my classroom with my science students. the amount of Data to track and graph, the water chemistry man the learning is endless. And the fun is as well.

JBKReef · Apr 23, 2018

A lot of times the water temp from an RO storage unit will come out colder than what your tank maintains at with the passive heating from the powerheads, return pump and lights. Also with having a lid on the bio-cube it will help with maintaining a temperature. If you have an outlet, throw that mini heater I included with your goodie package for the water change kit into the 5 gallon bucket for the water change.

I agree with the sentiments above as well.

-IO I think suggests to mix for 24 hours before adding to the tank
-drain from the front of the tank, but then add in a gallon at a time to the return section in the back of the cube. Might take 20 mins but will be an easier transition.

Be sure to turn off all equipment when doing the water change. Pumps running dry, or powerheads running while at the waterline will create lots of micro bubbles which could make the water appear cloudy.