Do you think a 50% water change every week would keep pH, ammonia, nitrite and nitrate at the correct level?

Answer 1

I think it is a little high to change out in one shot, but with the others saying it's too soon, I think they are not accurate. Ok as I explained in other answers, there are always going to be exceptions. But I really strongly feel, going to every 2 weeks is not a good idea. I think a good weekly 30-40% for your tank is just fine. Going up to 50% in one shot, you run a risk of too much of a temp difference, as well as a possible ph shift. The tap water, unless you run a thermometor in your bucket, is just a touch esitmate. In actuallity, it's probably more like a good 5-10 degrees difference between that and what is in the tank unless you take a good reading. It's hard to take a good reading because when you fill up your water to put in the tank, it's still settling, and takes more time to really let the temp in that water distrubute evenly to take an accurate reading. Also even though it's the same tap water you'd have filled your tank initally with, it doesn't mean it's going to have the exact same ph as what is in the tank. Your tank Ph in an established tank is well to have settled into what it's everyday reading is and probably doesn't match your tap exact. If you're adding half the volume of the tank as fresh from tap, and a shift of over .5 a point, that can do more damage then good. In a lower amount of change, there is less of an overall shift if there is a difference.

This is why I'd say you're better off with smaller weekly changes. I only do 50%'s myself if its like an emergency change out. You certanily are not going to harm anything doing say weekly changes at 30%. I can see you possibly doing more harm by waiting for those saying 2 weeks or a month. What they are not considering in this advice is this. Even though thier tanks are established, and even if it's heavily planted, it's never going to totally consume then end product, nitrates totally. And those nitrate accumulate over time. Even if you cut feeding down, one of the other big sources of ammonia is fish respiration itself. Longer term exposure to elevated nitrates can leave a fish with a weakend immune system. Should anything ever get in, you're liable to lose your fish more rapidly then you would if they had a stronger immune system. And on top of all that, waiting 2 weeks or 4 weeks to gravel siphon out the waste, it's really promoting conditions for unwanted pathogens to enter the tank. You really can't be too safe. One final note, changing the water on a weekly basis will also promote a good tank by replenishing vital compounds that are not otherwise replaced, such as calcium, magnesium ect which have many beneficial effects on your tank.

JV

Follow up:

Point in the case of exceptions, look at Ash. As I said there are always going to be those exceptions, but all in all, it's your call. You want to roll the dice and hope you don't imbalance your tank Chris, it's up to you. I can only tell you what I know from keeping small and large tanks as well.

Answer 2

I think you should listen to JohnV. One thing I will say is that when water is changed every week you don't need to worry about PH whether you change 25% or 50% of the water, because the water will always be fresh and the PH stable and that of your natural tap water. The longer a tank goes without water changes, the more you'll notice the PH change (usually it drops - acidity of fish waste and the cycle itself drive it down). Also, a cycled tank should have 0 ammonia and nitrite no matter how long you go without changing the water, since your biological filter should take care of this regardless - it's the nitrates (and other elements like phosphates) that will gradually build up. Question: Can you really have water that is too nice and fresh and clean? You can get away with bi-weekly or even monthly changes, but the best thing for the fish, and for preventing a gradual decline of tank cleanliness, is weekly maintenance including water changes and vacuuming.

Answer 3

You need to get yourself a test kit. That way you know what the levels are in your tank at all times.

25% weekly water change while cleaning is perfect aquarium maintenance. 70% is WAY TOO MUCH and 50% is not needed.

Your ph will readjust with a 25% weekly water change and remain stable. You will see it won't change much.

Ammonia and Nitrites unless your tank is cycling will take care of each other and the 25% water changewill drop the nitrate levels.

As long as you are not overstocked, keep to a weekly maintenance schedule including testing the water. If you see your ammonia or nitrites spiking, do a 25% water change.

Answer 4

50% is not too much on a weekly basis. I do this every week on my tanks and there ph is stable and nitrates stay low. It is in my opinion the best way to go and the healthiest for my fish. Most fish do best with the freshest water they can get- in balance with cycled water of course, after all they breathe the stuff!

*edit: Also when I do my changes I add back water that is already the same temp as my tank, therefor I do not have a problem with a temperature flux, and I keep mostly hearty fish like cichlids who do best with higher volume water changes (in my opinion).

Answer 5

it is not necessary!
ammonia & nitrite with BIOLOGICAL CYCLE in your tank is converting to nitrate (nitrate is not dangerus such as ammonia & nitrite) and you reduce it with water change.
You should be doing partial water changes anytime your water test higher than 0.5ppm for ammonia, and this will probably mean twice a week 25% water changes until your bacterial population rebuilds and biological cycle is not started.
when biological cycle become started ,30% water change every 2week is sufficient if your tank is not overcrowded. and if your tank is overcrowded you can have 20% waterchange every week.

in this website you can read about BIOLIGICAL CYCLE
http://www.fishlore.com/NitrogenCycle.htm

Answer 6

In an establish tank that would be fine. I've been keeping fish for over 50 years and I do about 70% water change every week. But I do it with about 10% every day. I use the water to water potted plants and such. My fish thrive and only die of old age.

Answer 7

It should keep pollutants very low in a cycled tank, but it is only necessary to do it that much in a heavily stocked tank. If you do it that much and often in a new tank, it will take forever to cycle.

Answer 8

Nope

Answer 9

Don't change your water so often!! Sounds like a new tank that has not properly "cycled"....let it go for about 2 months, the levels are going to jump....then do a 25% water change monthly, and that'll do it for you.

Answer 10

i would wait and change it every two weeks. at least that's what i do, but if you buy water conditioner, you won't have to do it but once a month