Longest you can go without water change

JEREMY82 · May 11, 2017

Ok so I have a trip coming up and I will be gone for a month... my problem is I got a 2 tanks 1 is for fragging and farming and is full and then I have my display tank... I know for a fact my friends are not going to be able to keep up 2 tanks cause none of them are in the hobby.so I plan on moving and jamming my 75 with everything ..there lots of corals in my tanks ... I got a dosing pump but have not had time to set it up .. or do all the work to figure it out. How long can tank go with out water change ?

takayan · May 11, 2017

I did not change my water for 3months for LPS tank.

Coronus · May 11, 2017

I would be cautious about jamming everything into the 75. The sudden bioload change can cause an overload and lead to sick and dieing corals very quickly. Then leading to a tank crash. Not sure of the capacity you are talking about. Just be careful. I have seen it happen.
As far as water changes, a month should be ok. Do a couple consecutive nice ones before you leave. Give these tank and sump a good cleaning.

JEREMY82 · May 11, 2017

I've been just putting a couple frags n at a time for a few days. The system holds good bioload, been running for I think 4 yrs

beaslbob · May 11, 2017

The only correct answer is indefinitely.

More important than water changes is feeding the fish, replacing evaporative losses, and any dosing for things like cal, alk, mag.

my .02

Donovan Joannes · May 11, 2017

Do it correctly and save some salt. A lot of things can go wrong for not doing WC, but master the skill, learn your tank chemistry and test vigorously for couple of months, maybe a year to tune up with element depletion and you can forget about WC completely. Quite a few in the market that promotes non WC system. Myself?. None has been done for more than 3 years.

Don S · May 12, 2017

Just went 3 1/2 weeks with no water change - no prob.

reefwiser · May 12, 2017

Years there are people who have gone years without water changes. If you test and adjust for coral uptake of elements you can do with out water changes all together.
https://www.reef2reef.com/threads/glennfs-300-gallon-dsr-reef.138700/

Bruce Burnett · May 12, 2017

I have not done one in 2 years. Make sure you have some way of collecting a months worth from your skimmer, I actually turn mine back where I get very little to be gone 2 weeks. I have a 40 gallon ATO and it will go 12-14 days on my tank and my system can go a week without feeding but I would not want to go longer than that. You want to clean your pumps at least one week before you go so buildup does not stop any while you are gone. Make it as simple as you can for whoever is watching you tank if you can portion out the food it will help.

melev · May 13, 2017

Add me to the list - I've not done one in 14 months. But I plan to get back to doing them.

turfster26 · May 13, 2017

melev said:
Add me to the list - I've not done one in 14 months. But I plan to get back to doing them.

Add me to the list too. Do to life getting in the way, and simply lost interest in both my 60-gl cube and 180-gl, I have not done a water change in over two-years.

In full transparency, I did have a full sps crash on my 180-gl 3-years and only have a rare Ritteri and fish only. And my 60-gl cube has lps only. But the fish are happy and the Ritteri split twice in three years.

I am NOT advocating WC every three years, but when I do get the juices flowing again and get my tanks back, I will most likely only do WC every few months or so. As on has mentioned here, if you have good chemistry, good husbandry and clean food, you should be able to get by IMHO with great intervals between WC. Granted SPS tanks may require closer changes, but YMMV.

mtraylor · May 13, 2017

Nothing to worry about. I don't do many water changes in my aquarium per say. But I do supplement and obviously have to top off water a salt etc. So essentially there are some small water changes. Enjoy your vacation and don't have your tank sitters do too much.

srad750c · May 16, 2017

I have gone a whole year, typically I only change 25% on a 90 day rotation. But I split it up into a two day change. My tank does better that way.

worthyfella · Apr 20, 2024

Donovan Joannes said:
Do it correctly and save some salt. A lot of things can go wrong for not doing WC, but master the skill, learn your tank chemistry and test vigorously for couple of months, maybe a year to tune up with element depletion and you can forget about WC completely. Quite a few in the market that promotes non WC system. Myself?. None has been done for more than 3 years.

I'm currently setting up a 200l heavy planted aquarium with around 30-40 small fish. I've seen such set ups go for a year with a perfect balance and crystal clear water.