when to change water

[fishtender]

I test my water about every other week or so. Sometimes I think my corals are looking a bit different and watch them for a few days and when I do the water tests, all is fine. I am beggining to think that maybe they just have up and down days like we do. Biorythms or something. Is this the norm for everyone?

When I test my water, I test for

PO4
PH
CA
ALK
Nitrate
Nitrite
Aumonia
Salinity.
(I top off with fresh RO water.)

All of these remain consistantly perfect. As long as these are stable, is there any reason to do regular water changes?

Aside from cleaning my skimmer cup and using my algae magnate, and fresh water top offs, my tank is nearly maintainance free.

Is the water change a crucial neccessity that I should be doing anyway?

Howard

 

[WarOrks15]

well most ppl here would say to do a 10% water change every week or so just to keep the no2 down. and by doing a water change every one and a while puts more CA in the water from the salt mix and replenshes the trace minerals that the skimmer can take out

 

[Doan]

Yes you should be doing a small water change frequently.. It takes out some waste and also the salt mixes are fortified with extra additives and such that contribute greatly to the health of your tank. These are depleated over time by your corals and such and regular water changes will help to keep the lvls more stable so the corals can thrive. I will also attest to the fact that my corals look a bit different right after a water change as well but within a few hours they look better than they did prior to the change.. I try to siphon as much in to the tank by reversing the vaccume and keeping the hose with the incoming water as far away as I can from the corals and that seems to really help.

Doan

 

[TheMadNucleus]

Yep - I agree with Doan and have a bit more to suggest.

As Doan said - the trace minerals that appear in your saltwater as a result of the salt mix you use are volitile. In effect they are 'used up' either directly by the tank inhabitants or by other chemical processes in the tank.

Recall that our aquariums are closed systems and as such the only link to the 'real world' is via a water change.

So my additional though: Naturally you will have to top off your tank periodically with new water. As you do this (even if you are using an RO) you are adding elements at an increasing rate. They will continue to build up in the tank and there may be things which are not healthy but not detectable via your testing kits. For example: some forms of pesticides are not filtered by RO units, if you have some of these in your water at a low enough level not to do any harm but you never change water in your tank they will continue to build each time you top off and may cause harm later.

Just an additional motivation.

Tom