How often and how much water changes?

[alexgcali]

50 gallon.
17 1-inch fish, 3 2.5 inch fish.
Emporer 280 power filter with E size filter and extra carbon filter.
No plants. White gravel substrate.
4 hrs/day 17W coralife light.
75 degrees.
Nitraban w/ new water.
Stresszyme (25 mls) once a week.

How often do I need to change water and
how much at a time?

Someone said, every 6 weeks and 15 gallons.
I feel like I could go 8 weeks tho.

Advice?

 

[mfdrookie516]

You should be doing weekly water changes IMO. At the very least, every other week. Who in this world told you 6 weeks??? I do 50% weekly in all my tanks, sometimes twice a week if I feel like it and they're not heavily stocked at all.

 

[alexgcali]

It has been 6 weeks and the fish are very healthy. The previous owner of the tank did the changes every 6 weeks.

 

[fort384]

I think 6 weeks is a long time. Are you topping off the tank between water changes? Remember that topping off without taking water out is not good for the tank. When water evaporates, none of the metals/ions/particulate that is inevitably in the water goes with it.

That being said, topping off every now and then and going a week or a few weeks between water changes isn't terrible either. It is all dependent on your water quality, the bioload in your tank, whether or not you have live plants or are adding any chemicals/additives to the tank, etc etc.

Basically, you will get differing opinions on this, and you have to decide what works best for you. I personally have always done about a 20-30% water change in the tanks I have run every week. But, I also have heavily planted tanks that I dose with fertilizer.

Bottom line, I would recommend more often than every 6 weeks, but 50% a week isn't a necessity for every tank either...

 

[Faile]

Since you don't have plants, the best indicator would be the Nitrate levels. You want to keep them under 40ppm, preferably under 20ppm. The more heavily stocked your aquarium is, the quicker the Nitrates will build up. Since the water changes have been pretty lax for awhile you might have to do some more frequent and/or larger water changes to get the Nitrate down to acceptable levels.

 

[alexgcali]

Nitrates @ 40 ppm, Nitrites at .25 ppm....

and changing water.

 

[Mark Hewitt]

Small weekly changes are better than big infrequent ones. Fresh water is always a good thing!

As said above let your nitrates be a guide as to how much to change each week.

 

[happygirl65]

Weekly in a non planted tank is overkill unless you are heavily stocked. I would say every two to three weeks will keep you runing smoothly but do keep an eye on the levels. If you are seeing nitrite at .25 you are showing the effects of an ammonia spike...so if you detect ammonia or nitrite at all do a water change of 50% and retest daily to see if more is needed. Once your bacteria catches up again you can return to your normal water change schedule but I would not go longer than 3 weeks if you want to keep them thriving and don't want to have to test the water all the time to see if it's time to change it...it's just easier to put it on a schedule.

 

[Bigzmey]

I don't think weekly PWC in a non planted tank is an overkill. Weekly 10-20% PWC is fast and not that hard. You will be rewarded with happier healthier fish. Obviously it depends on stocking.

 

[Osage_Winter]

Here's something I was going to begin a new thread on, but came across Fort discussing it here:

Remember that topping off without taking water out is not good for the tank. When water evaporates, none of the metals/ions/particulate that is inevitably in the water goes with it.

Very interesting. I recently let about 5 or 10% of my tank's water evaporate naturally, and then just topped off the tank with fresh conditioned water, thinking that by letting the evaporation occur, it acts like a "natural" water change -- but then I came across Fort's comment here, and I see that was not a good idea...

What I don't understand is that if when water evaporates it leaves behind the metals, etc., then why does actually changing the water get these substances out? It would occur to me that these metals, etc. would simply attach to glass, other things etc. in the tank that the water change wouldn't remove anyway -- I know I gotta be way off here, but can someone explain to me the theory behind topping off without changing the water being a bad idea?

 

[adeebm]

The metals, minerals, etc are dissolved in the water. Think of it a them floating around in it. When the water evaporates, just the water molecules get plucked off. The metals and minerals are in solid form and don't evaporate with the water. Their concentration in the water will just increase as more water evaporates.

That's why it's best to top off with RO water, because RO water has little to no minerals and so you won't increase mineral concentrations. You still need to change the water to keep it clean and remove fish waste. When you change the water, you are taking out water mixed with all the minerals and waste.

It's like putting sugar in your tea. THe sugar dissolves, but it's mixed in with the tea, not stuck to the side of the cup. If you were to let the tea evaporate, you would have sugar left at the botom of the cup.

--Adeeb

 

[Osage_Winter]

The metals, minerals, etc are dissolved in the water. Think of it a them floating around in it. When the water evaporates, just the water molecules get plucked off. The metals and minerals are in solid form and don't evaporate with the water. Their concentration in the water will just increase as more water evaporates.

That's why it's best to top off with RO water, because RO water has little to no minerals and so you won't increase mineral concentrations. You still need to change the water to keep it clean and remove fish waste. When you change the water, you are taking out water mixed with all the minerals and waste.

It's like putting sugar in your tea. THe sugar dissolves, but it's mixed in with the tea, not stuck to the side of the cup. If you were to let the tea evaporate, you would have sugar left at the botom of the cup.

--Adeeb

What is "RO" water?

 

[adeebm]

Reverse osmosis water. Sort of like distilled water. You can make it at home with a reverse osmosis filter, or just buy distilled from a grocery store.

--Adeeb

 

[BillD]

Over time, the amount of Total Dissolved Solids will increase, when replacing evaporated water.

 

[Osage_Winter]

Reverse osmosis water. Sort of like distilled water. You can make it at home with a reverse osmosis filter, or just buy distilled from a grocery store.

--Adeeb

Gotcha.

 

[Osage_Winter]

Over time, the amount of Total Dissolved Solids will increase, when replacing evaporated water.

So, that's why the actual changes are necessary, and not just replacement water from evaporation?