Water Changes

[phixman]

Are water changes necessary considering we can dose and export nutrients through macro algae, gfo, carbon, etc?

What other benefits do water changes have other than adding Calc,Mag,Alk, and exporting nutrients?

 

[Blizzahjh]

trace elements is a big one. Some speculation that gfo strips some of the elements. Even while running low nutrient and dosing all the main elements ive read multiple times people get best growth while also doing water changes. I do not have much sps but i definitely see a noticeable growth difference right after a water change and my alk/ca/mg are all stable.

 

[TexasTodd]

Necessary? No. Easier that the alternative? Yes.
I think there's too much talk of this that new reefers grab onto.

No WC can be done extremely well and with results as good as any system out there, but you really need to know what you're doing and be very attentive and/or a lot of extra equipment. I also think you really want a very mature tank.

WC help fix mistakes / bumps along the way to a matured healthy system.

 

[WVNed]

When marine animals are kept in a tank, a fixed volume of water two things happen. Elements in the water are used up and waste goes into the water.
Doing water changes corrects both of these things at the same time. I do large weekly water changes of 20-30%. Sometimes I do them twice or 3 times a week. It is my attempt to keep the water in my tank close to sea water as I can.
It has worked for me for a decade with small tanks.
It seems it is almost a badge of honor in aquaria to not do water changes. I don't get it. That would be like bragging that I never feed my dog.

Yes you can correct both things other ways by doing systems to add and take away stuff from the tank. You are also adding multiple points of possible failure.

But with small tanks ( keep in mind a 75 gallon is a small marine tank) with higher bioloads it can be difficult to do. All of these systems to add and take away have to be in balance. You have to add small quantities of accurately measured amounts daily and do regular testing because the rate of use changes over time. If your ATS blows a pump you cant screw around for a week looking for a new one. The smaller a quantity of water you are working with the more easy it becomes to over or under dose or accidentally strip all of a needed element from the tank.

If you are a person that can be accurate and persistent over years and never miss a day more power to you.

I am not and I know that.

 

[OPtasia]

With a big enough completely mature stable tank, yes you can employ certain techniques to avoid water changes. Or, you can just do water changes. Most of us are using simple, reliable water changes with a good quality synthetic sea salt and RO/DI filtered water as an inexpensive means of maintaining a tank.

Even if you don't like doing water changes, there are solutions in the marketplace for you, too. For example, there are controllers that can automate the water change process (apex, etc.) to make water changes as hands free as possible.

 

[cracker]

My tank just looks better as a whole after a water change . I suppose it's very possible to skip w/c's but I'm not that experienced .

 

[hart24601]

I would echo other replies and say they are not necessary, however compared to the alternatives they tend to be a cost effective and easy solution at least until tank size gets quite large, and even then it can be worth the cost just depends on the individual and what equipment/cost. IO at around 20 cents a gallon (less when on sale) is pretty hard to beat to prevent most minor elements from depleting or accumulating.

 

[Hitman]

No water changes here. I dose ESV B-Ionic which I believe is the only 2 part that includes minor and major elements ( At least their website claims this ) I know I sent off a ATI ICP test and other then being low on I and MN which I had to dose 1ml of each for 2 days and a bit of metal that showed up do to a bad magnet I’m convinced there’s no need to do a water change. Oh and the water I sent off was from a tank that has not had a water change in 5 years.
I have chaeto and red mangroves in my refugium under a Kessil H380, way more flow then most but after watching a interview with Jason Fox on his flow I tried it out and my tank loves it. I’m guessing I have 2,500 gph going through my sump and I’m at 60% turnover per hour in my tank.

 

[phixman]

I’ve always found it interesting that almost all sps keepers , even with success such as WWC do water changes weekly. I never understood the reasoning, but they have nice corals. I’m personally running a 20 gallon, 2 part dosing , and some chaeto. I’ve gone 7 months without water changes before . Most of my nitrates and extra nutrients gets sucked up by my deep sand bed. Are there important elements and other things that water changes add that 2 part doesn’t ?