The Whole Water Change Thing

20% every 3 weeks or when I can see it is time.

 

Does anyone here do lower salinity changes? I mean, the salinity in the tank is climbing up, let's say1.026, due to evaporation. Could you do a 10% water change but with water mixed to a SG of 1.020 to help bring salt levels back into range?
It rains on reefs, just like everywhere else. Fresh water flows onto reefs and lagoons all the time.(At least during rainy season). If the lower density salt water is added slowly, it really shouldn't affect anything, true?

 

on my 135 I haven't done a water change yet, and don't plan on, unless something dies. I do change my quilt batting often, bout 1x every other week, if it's nasty. So far so good!

 

I know this is an old thread, but ongoing issue nonetheless! I believe Tangster's theory is that water changes only need to be done in cases of extreme emergency, if something needs to be taken under control ASAP. If you are doing regular water changes to keep nitrate down then you are band-aiding a problem: high nitrates. If you get a good skimmer going and/or a good denitrifier then you will not have to worry about the nitrates, they take care of themselves. Same with any other issue. If you find a permanant solution to the problem then there are no problems to band-aid with regular w/c. Of course you will have to dose accordingly to keep params in check, but I find this easier, cheaper, and less stressfull IMO. I have bought salt once since my tank started at the first of the year and still have almost a half bucket left.
So this is what Tangster told me and I think it makes good sense, this is my philosiphy(sp.?) to a T. Who enjoys 20g water changes anyways;D especially if they are not necessary!;D

 

Id like to resurrect this thread as I am now in a mental debate on how to handle my water changes. From what I gathered from this thread so far is this:

- some people change their water weekly (5%)
- some people change their water monthly (20%)
- some people change their water NEVER

I read that article on water changes, and in my opinion im going to go with 5% weekly based on natures habits. Those reefs do get cycled often and do get freshwater now and then dropped atop of them.

I need to confirm this though. As long as my mix reservoir has water of the EXACT same SG/TEMP I should be able to siphon 5% of my water, replace it with equal volume of water from my mix reservoir and see 0 change in SG/TEMP in the DT?

 

Correct

 

So when evap occurs in the DT its not actually evaporating any salt right? hence why we top off with fresh RO/DI water? this keeps the salinity right because the volumes not changing from evaporation if its on a ATO.

without my ATO in place id just dump in a cup or two of RO water to refill my sump and i was having minor shifts in SG and i couldnt figure out why. with an ATO in place its more constant because as evap happens its being immediately replenished with water volume.

i understand now why we dont topoff with the same SG/TEMP water we have pre-mixed. the salt would continue to raise perpetually over a short period of time if i topped off with the mixed resevoir.

im learning....

 

yep..you can change the salinity during a water change, the trick is to do it slowly though if that is the case. ocean changes salinity often enough, (it is actually a higher salinity in the rainy season because of evaporation - maybe not in the inland waterways, but out in the big blue it usually goes up. Inland waterways change very often their salinity...4 times a day), but the change comes at best over hours....so try to make yours go slowly too, like you are acclimating the whole tank.

 

good to know, thanks john!

 

Exactly.
That thought process happens at one point or another I'm sure with every new reefer. I remember thinking the exact same thing.