Are water changes a waste if undetectable nitrates/phosphates?

[Jorda320]

Hi all,

I've got a nano with just two clowns and some hermits. It has some macro algea and so far nitrates and phosphates are undetectable. It's been up for over a year and I've been doing a 5 gallon bucket water change every two to three weeks but I'm wondering if even that is a waste? No algea issues or anything negative going on, just an easy little tank for my clowns. Thinking about just letting the ATO manage salinity and testing monthly. Any thoughts?

 

[Gtinnel]

I do water changes even when I had to dose nutrients because it's a way of reducing the unknown elements in your tank. For instance for nitrate I used to dose potassium nitrate and I was concerned about potassium building up to higher levels than wanted.

Honestly your tank would probably be fine with or without water changes but IMO it's about more than reducing nitrate and phosphate.

 

[Pistondog]

Test and try to lengthen the time between changes.
We have a 10 g waterbox with clowns and zoas. It gets a change maybe every 4 months. No dosing, just feeding the clowns and ato.
Even a couple of lps.

 

[Jorda320]

These both sound like good points. I'll keep on top of testing and maybe just do a 5 gallon change every two or 3 months just to be sure things stay good.

 

[Nburg's Reef]

I do water changes for the stuff we don’t test. My ICP tests always come back normal, but my Zoas and a few others just do better when I do water changes.

 

[damsels are not mean]

If you are not growing a lot of calcifying corals and also aren't seeing any nitrates then I think water changes don't really do much for your system. At least not frequent ones.

 

[EeyoreIsMySpiritAnimal]

Water changes can replenish elements that are in the salt mix. They aren't just for removing undesirable things. But, as damsels said, if you don't have corals that need the calcium, alk, trace elements, etc, then you should be ok.

 

[ians pico]

Test and try to lengthen the time between changes.
We have a 10 g waterbox with clowns and zoas. It gets a change maybe every 4 months. No dosing, just feeding the clowns and ato.
Even a couple of lps.

How often do you do top offs and do you have a lid?

 

[X-37B]

I do 10% a month on my 3 systems. Mainly to remove things that may build or that we cant test for.
My systems are:
120 sps
45 frag
20g nano.

 

[Pistondog]

How often do you do top offs and do you have a lid?

Screen mesh lid. All the tanks have ato's, the 10g has a tunze 3152,

 

[mehaffydr]

I think that the reason everything is going good right now is that you are doing the water changes. You are removing things you don't test for and also replenishing things you don't test for.
If you stop the water changes things will slowly build up and or or deplete and then you will have a problem. The steady water changes that you have been doing are keeping things balanced which is the key to a successful reef.