Am I Doing Unnecessary Water Changes?

[ShaggyRS6]

My tank has been cycled now for about 5 - 6 weeks. All my parameters are stable, Nitrates are somewhere between 5-10. My Phosphate is lower 0.25 but great than zero and I keep a bag of carbon in the sump (Reactor coming next week) My corals are doing great, with one exception, cant seem to fine the right spot for the Strawberry Shotcake, I am seeing growth on everything.

As my tank is so young I have been doing 10G water change weekly. After the water change I see a slight negative reaction from the corals and the orange sponge of my live rock. Things perk up again about 2 days after the change.

So with all this in mind, I am wondering if I should leave the tank for 2 weeks without a change, or just do 5 gallons. Would love to hear your thoughts.

 

[MuffinMonster]

What size tank is it? Are all the corals small frags or any colonies?

 

[ShaggyRS6]

Just 2 colonies, And 5 frags. 100G

 

[Halal Hotdog]

0-.25 ppm phosphates is a pretty big range. I would get a more precise tester to get a better idea. Mine runs higher, but prefer to keep phosphates at .03 ppm. There is a lot of variables that go into eliminating water changes. What is your fish load? How big is your tank? What is the filtration. Do you have a refugium? How much do you feed? Young tanks need more water changes then more established (2+ years) tanks from my experience. It is possible to severely limit water changes, but testing becomes paramount.

 

[ShaggyRS6]

I test nitrates normally nightly and phosphates every other day.

4 small fish. One medium Tang.

 

[BeejReef]

a little unusual to hear of a negative reaction to water changes.. a lot of peeps say their tank seems to perk up.
I have no experience trying to run zero water changes, so can't really comment on that.

Are you certain that your salinity and temp are well aligned before your water changes? Do they tend to really stir up the tank? Are you sure your ato is off and not running while your sump level is drawn down?

 

[Brien]

A 10% water change weekly should have no adverse effect on your tank.

 

[ShaggyRS6]

I’m in no way saying it’s a major swing. Just I notice that there are slight changes. Especially in the sponges . Just a very subtle change.

Salinity, temp, salt mixed for 24 hours. Everything the same. The only thing I could think of was that I maybe taking out nutrients those sponges like, and it takes a couple of days for that to build up again.

 

[BeejReef]

that's interesting.
I'd be curious to see how it goes if you try cutting back on water changes.
Conventional wisdom says it's best to do them, at least for the first year or so. But if we always stuck w convention, it would still be all closed loop, metal halide, and undergravel filters

If I were to try it, I'd probably send out icp tests 3-4 times a year to make sure I didn't have anything undesirable building up to toxic.

 

[ReefHomieJon]

I have a 125g DT and a 100g sump. I’ve done one 55g water change(over 5 days With an awc) since I started it up in mid august. I let my water test dictate when to do a water change. My tank is doing great. But I do have a large volume of water due to the large sump which helps keep my tank stable.

 

[ReefHomieJon]

How big is your sump?

 

[ShaggyRS6]

How big is your sump?

22G

 

[ReefHomieJon]

22G

You’ll prolly need them more often then me. If not for removing nitrates n phosphates then then for the calcium and carbonate getting consumed by you corals unless you’re dosing. I don’t even dose yet because my coral have a large “reserve “ of calcium alk and mag in all that extra water I have. But as already stated 10 gallons a week is more or less 10% a week so I doubt that that’s hurting your corals unless you’re not matching parameters during the WC. I think less is more with reefing tho(if it ain’t broke dontt fix it). Only do WC when testing says you need it. And if you don’t maybe one 50 % (over the course of a few days) every few months For good measure. I may do a 55 gal change this week Thanks for the inspiration
Prolly will replenish some trace elements

 

[ShaggyRS6]

Not seeing a drastic change in Calcium, Alk, Mag etc. Latest I have left a water change has been 9 days.

 

[ReefHomieJon]

Then I would just chill lol. People be overly scared to let their tanks be. Unless you have some serious bioload idk why people see the need to do so many water changes. Especially with all the money they spend on filer media, reactors, and dosing. That stuff is meant to add good stuff and remove bad stuff. Why work so hard on your water just to constantly remove it?
Here’s an idea, do t change for water for 2 weeks and do a water test. If it’s still good let it go a third week. Test it. If it’s still good let it go a MONTH. Test your water. If it’s still good we’ll that’s showing you that you don’t need that many water changes but if you’re starting to get scared because you’ve never went so long without one or whenever you begin noticing a trend that you wanna correct before it gets out of hand then start doing small water changes until you’re back where you want to be but I’m sure you’ll find that less is more and your corals will probably look better and do better. Just my anecdotal opinion that’s actually based on research that a lot of reefers tend to ignore or dismiss because in this hobby we’re told that spending money equals more success whether it’s on the latest reefing tech or on something as simple as water. But less changes equal more stability in my tank. Maybe because of my large sump tho. Anecdotal. HOWEVER, a lot of people are trying this approach and the people I’ve talked to say their tanks are doing better as well

 

[HB AL]

I haven't done a water change in over 2 years so I'd say ya it's a waste.

 

[ReefHomieJon]

I haven't done a water change in over 2 years so I'd say ya it's a waste.

That’s right lol

 

[mfinn]

I do water changes every 2-3 weeks. Not terribly big ones, maybe 15%.
I feed fairly heavy. 2-3 times daily.
I've been doing it this way for several decades.
I see people say they don't think it's necessary, but I'm happy with my tank.