Water Change Vs No Water Change

Hey all. This subject was brought up at work today and I wanted to run it by all of you.

Do any of you NOT do water changes?

The discussion at work was whether water changes are necessary for a successful/healthy tank.

I'm personally a bit biased at the moment. I have a 10 gallon that's been running for about 8 months with exactly zero water changes. It's a very heavily planted tank with one Betta, six Harlequin Rasbora, 5 false JuliI Cories, and two African Dwarf Frogs. Weekly water parameter checks confirm water quality is staying right where it should be. The tank is being filtered by a Marineland Penguin 100.

BUT, I have a non planted 3.5 gallon tank with one Betta and 2 nerite snails that I do weekly ~25% water changes on.

Both tanks are thriving and showing no signs of any problems.

So what's the general concensus? Are water changes absolutely necessary? Does it depend on the setup? Does it not even matter?

Chime in and let's discuss.

 

Depends, I can leave my 20 gallon for a couple weeks without water changes because it is more high tech. But my 10 gallon betta tanks don't have much so they need weekly water changes. But some have super high tech tanks. The time I skipped a water change it caused a mess of the tank levels... And then the attack of the algae....

 

You could get away with 0 water changes, but you have to top off the water to replenish the minerals, rinse the filter, have lots of plants & have a low stock level. I haven't had to do a water change on my 23 for three weeks because nitrate never goes above 20.

 

It definitely depends on the tank.

If you have a heavily planted 100 gallon tank that only houses 100 ghost shrimp, you'd probably never need a WC. You might want to consider calcium and other nutrient supplementation, but water changes in and of themselves wouldn't be necessary.

Take that same tank and add 200 cardinal tetras, 2 full-grown angels, 150 SterbaI Corys, 300 Marbled Hatchets, and a pleco, and you'll be needing to change water out relatively often. If not, then you're going to have some very serious nitrate issues, even with a lot of plants.

Let me say this, as well: Water changes can almost never hurt under normal circumstances. One of the first things that I do when I see a problem in my tanks is a water change. Unhappy coral/fish? Water change and water test. Lots of algae? Water change and test for nitrate and phosphate. Unhappy plants? Check for potassium and other macro nutrients, as well as nitrogen sources. A water change helps here so that you're replenishing vital nutrients usually found in your tap water.

 

No water changes for 8 months on a 10 gallon with that stock and no water quality issues??? I don't see how that is even possible even if it is heavily planted.

 

No water changes for 8 months on a 10 gallon with that stock and no water quality issues??? I don't see how that is even possible.

I'm surprised it works in that tank. Maybe there's a ridiculous amount of plants, I don't know ¯\_(ツ)_/¯

 

No water changes for 8 months on a 10 gallon with that stock and no water quality issues??? I don't see how that is even possible even if it is heavily planted.

Agree seems a bit fishy, Exspecially with that stocking. hmmm the wonders of fish keeping.

 

Water changes are just to add new water into the tank and removing some of the old tank water.

 

No water changes for 8 months on a 10 gallon with that stock and no water quality issues??? I don't see how that is even possible even if it is heavily planted.

It's no fish tale(pun intended). Naturally, I've topped off the water due to evaporation, but otherwise, everything checks out. It's a low tech tank with very simple plants( bacopa, java fern, and anubias). All the fish are happy and growing at a good rate(I bought many of them at a small size).

Thus far, there haven't been any signs of stress or problems.

Edit: to be fair, the rasbora were only added roughly a week and a half ago.

 

It's no fish tale(pun intended). Naturally, I've topped off the water due to evaporation, but otherwise, everything checks out. It's a low tech tank with very simple plants( bacopa, java fern, and anubias). All the fish are happy and growing at a good rate(I bought many of them at a small size).

Thus far, there haven't been any signs of stress or problems.

Edit: to be fair, the rasbora were only added roughly a week and a half ago.

that is the other reason why I add water to. The 60 gallon evaporates so quickly sometimes.

 

that is the other reason why I add water to. The 60 gallon evaporates so quickly sometimes.

Water seems to evaporate much quicker now that's its deep into summer and the AC is running is running more often than not around the house.

 

Water seems to evaporate much quicker now that's its deep into summer and the AC is running is running more often than not around the house.

Same! grrrrrrr

 

Water seems to evaporate much quicker now that's its deep into summer and the AC is running is running more often than not around the house.

Same! grrrrrrr

 

Here is my experience. I have a very lighly stocked 75 gallon and I do roughly 25% water changes monthly. It has absolutely nothing to do with the normal stuff we test for but since most don't test beyond what a test kit tests for they will never know till disaster strikes. If I start going much beyond the month point I notice a rise in total dissolved solids, a decress in ph and a decress in dissolved oxygen. Granted it not much but if left to continue would eventually get to a point were it would be an issue. May take a year to get to that point but it would eventually get there.

 

I usually get away without doing WCs on my tanks because of the plant density for my planted tanks.
Some tanks aren’t planted, but all of my tanks have low stocking levels and they are very overfiltered.

 

Here is my experience. I have a very lighly stocked 75 gallon and I do roughly 25% water changes monthly. It has absolutely nothing to do with the normal stuff we test for but since most don't test beyond what a test kit tests for they will never know till disaster strikes. If I start going much beyond the month point I notice a rise in total dissolved solids, a decress in ph and a decress in dissolved oxygen. Granted it not much but if left to continue would eventually get to a point were it would be an issue. May take a year to get to that point but it would eventually get there.

This is the type of info I was hoping this question would instill.

Regarding the dissolved solids, do you think treating the tank for a metal neutralizer would be effective enough to keep water changes at bay? Or do you think they would still be necessary?

I personally think they would still be required.

 

Not sure what a metal neutralizer would do since dissolved solids aren't necessarily just metals but mostly minerals. Plants and fish use up what they need and leave behind what they can't use so you end up with an imbalance. That and I would rather just change a little water instead of adding things. I have a well so I don't even add a dechlorinator since I really don't need to.

 

Well my tanks aren't planted but I've got a 110g Hap and Peacock tank and they are big hungry waste producing machines. That being said I do almost 50% water change every 3 days regardless of my readings, I just personally can't see not adding fresh water considering in nature there's constant "water changes" I also out of habit do the same for all my tanks. I can't imagine going over a week with any of them, sounds nice though. Lol