Water Changes, Vital? Preventive?

[NS Mike D]

I confess, after three solid months of weekly water testing and 25% water changes with RODI water, I let things slide for a month not testing and doing no more that cleaning the glass and topping off the tank (and of course feeding).

I tested the water today, which seems ok, and the tank inhabitants are doing well fish, inverts, corals (soft, mushrooms, lps & sps). It's a bit overstocked, but I like all the movement and the fish are showing no signs of territorial issues.

My tank is 29gal, with lots of live rock and a deep sand bed, I have a large HOB refugium with sand, live rock, algae, foam (for mechanical cleaning) and a carbon bag. I also have a phosphate reactor.

SG = 1.024
Ph = 8.0
Ammonia = 0
Nitrites = 0
Nitrates = 0
Phosphates = 0
Calcium = 420
Mg = 1080
Alkalinity = 3.0 8.4


Are weekly 25% water changes unnecessary, too frequent or vital? What may be building up that I am not seeing from my visual observations of the tank and water tests.


What should I look for to know when to change water or am I playing Russian Roulette with some stealth tank killer?

 

[Auston]

What kind of setup do you have. Sump with skimmer?.

 

[gone fishin]

IMO Once your tank has stabilized and got most or all of your critters in then you can play around with WC frequency/volume. I personally do 20 gallons every two weeks. Once you get to know your tank it will let you know. You may start to see a bit more algae grow, maybe a coral not opening up as much there will be subtle indicators. just my 2 cents worth.

 

[m0nkie]

I think 25% weekly is a bit too much. maybe 25% every 2 weeks or 10% weekly.

 

[seahorsedreams]

Think of it as them peeing and pooing and then living in the water. Albeit, some of the byproducts of that are testable, it's not all. It's proven that declining water quality causes stress in fish. Stress can have long term and often irreversible effects on fish health, depending on the length of time they are exposed to said stress.

They also get important minerals/electrolytes from the water, which will be replenished with a water change. It's easier to change water than deal with the effects later. However, 25% every week is unnecessary in most setups.

 

[Auston]

Sorry I missed your tanks specs in your opening post.
I would say for your set up a 20% water change every two weeks. I have a similar set up and find that works best to keep tace elements at the right levels as well as calcium and alk.

 

[ericarenee]

I do 10% every two weeks. If i see a sign of algae or anything else i will step it up to every week a few times. And Run a bit of gfo and change out my carbon early...

So I AGREE With everyone else 10 percent every two weeks i think is good. Just keep really close eye on your tank.. Ease in to lower water changes

 

[cloak]

This hobby & water changes just go hand in hand IMO. If you don't want to do the work I don't know what else to tell you. It's a marathon not a sprint. There will always be some threads where water changes is of no concern, but let me know how your tank is doing after five years, maybe ten. (no exceptions)

On a side note; sometimes the best thing to do is nothing at all. Definitely keep that in mind while your trying to balance things out. (nature will take it's course) GL.

 

[CStrickland]

For me, the easiest indicator is algae on the glass, and nitrates. If I don't do 10% a week they start to creep up, so I take that as a sign that the waste input exceeds output. I feed ALOT though. It's also in the zone for replacing trace minerals like iron and strontium through the salt mix cause I don't want to have to dose those like the "no water change" tanks do. A little kalk here and there keeps the big three in line.

Your tank won't be the same as anybody else's. If you're going to play around with it, I'd spent a solid couple of weeks testing all your parameters so you will have a solid baseline to compare if you feel like things are starting to go sideways.

 

[Ron Reefman]

There are tanks where people do very few or no water changes. They are typically much bigger systems with a lot more water and quality filtration techniques. And they are always very mature tanks, more than a couple of years old and have people who competely understand what is going on in their tank.

I think every 2 weeks is fine for yours, for now. When you have been successful with it for a year or two, then you could try cutting back to every 3 or 4 weeks. Just remember, in a tank of 29 gallons, you don't have a lot of room for error. If a snail dies, it can cause some issues in a 29g tank. In a 400g system, nobody even notices the change because it's so diluted.

 

[tmz]

Water changes add major ,minor and trace elements in the ratios you started with and export excesses. They also export some nutrients but are not usually the primary means for keeping a balance between imports from food and export via biofiltration and other means.
How much water needs to be changes is debateable. Most do 20 ato 40 % per month;some a lot less; some more. Smaller more frequent changes are better for constancy in overall reef chemistry. I do 1% per day plus a little extra now and then realted to maintenance ,FWIW.

 

[wicz101]

mileage may vary, but I do smaller weekly water changes and my tank seems to " thrive" and growth is noticable over a short period of time. When I get busy and/or lazy, water changes get further apart and there is noticable differance and grow slows, almost stopping.

 

[CStrickland]

They also export some nutrients but are not usually the primary means for keeping a balance between imports from food and export via biofiltration and other means.

Good point, I left out the part where I vacuum up detritus when I change the water, that's prolly doing more for nutrients than just swapping liquid. Nitrates wouldn't stay in the single digits just from changing 10% a week without at least a skimmer I bet. Not to start a whole "clean your sand debate" just giving the big pic.

 

[NS Mike D]

thanks good insight in the responses