# Water Change Question



## mzamzam123 (Mar 4, 2020)

Hello everyone, I wanted to know how often do you do a water change and how much do you change out in your thanks. I have a 75 gallon tank with a fluval fx4 running in it. Currently I have 13 cichlids in it and 1 clown loach which are all about 2 inches long. Also if anyone has any tips on how to properly add water back into the tank. The water from my tap doesnt have a high enough PH so I'm not sure if I should fill up buckets with water and then use API PH up or can I add the water directly to the tank and then add the PH up. I was advised to add crushed coral to my tank to help maintain the PH but I'm not sure if that is enough to keep the PH in a healthy range.


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## Deeda (Oct 12, 2012)

You never answered the water test results in the other topic you posted for your tap water test results.

What is ammonia, nitrite, nitrate and pH? If you have a hardness (GH) and alkalinity (KH) test kit, post those results also.

I also recommend leaving a sample of your tap water overnight in a clean glass container and repeat the above tests as they may change due to off gassing.

Depending on your tap water test results, you may or may not need to adjust the pH AND if you do, there are cheaper products to use than aquarium related purchases that can do more harm than good. Chasing pH is a double edge sword as the fish can experience harm due to swings up and down.


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## mzamzam123 (Mar 4, 2020)

I checked using the tetra test strips this morning and my readings were as follows:
Ammonia- 0
Nitrite- 0
Nitrate- 0 to .5 ppm
PH-about 7.8
Hardness (GH)- around 150

I dont recall the alkalinity reading. I really need to start writing the readings down.

Out of the tap my PH usually reads in the 6.8 range though. Is that safe to put back into the tank without adding anything to increase it?


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## Deeda (Oct 12, 2012)

Definitely start keeping a log of your test results both for tap water and tank water parameters just to see any changes that may occur, especially if you are relatively new to testing.

Were those the test results for your tap water or your aquarium water?


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## Old Newbie (Feb 18, 2017)

I don't see anything wrong with those numbers; I change 50% of the water in my tanks when it gets between 10 and 20 ppm nitrate, which is usually weekly.


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## mzamzam123 (Mar 4, 2020)

Those results were from my aquarium water.


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## Deeda (Oct 12, 2012)

Please test your tap water and post the results. Also set aside a sample of your tap water and test that in 24 hours to see if the pH or GH has changed. I would also pick up a KH test kit so you know the alkalinity of the water as it can help keep pH more stable if the values are correct.


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## mzamzam123 (Mar 4, 2020)

I tested the water in my tank again this morning and my tap and the results were as follows:

In the tank:
Ammonia- 0 to .5ppm
Nitrate- around 10 ppm
Nitrite- 0 ppm
GH- 150 ppm
Chlorine- 0 ppm
KH- 80 ppm
PH- 7.4

From the Tap:
Ammonia- 0 to .5ppm
Nitrate- 0 ppm
Nitrite- 0 ppm
GH- 50 ppm
Chlorine- 0 ppm
KH- 20 ppm
PH- 6.8


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## Deeda (Oct 12, 2012)

Did you also leave a sample of your tap water out overnight so you can test to see if the values change?


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## mzamzam123 (Mar 4, 2020)

I left water from the tap out overnight and tested it this morning but the results were pretty much the same.


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## mzamzam123 (Mar 4, 2020)

I just wanted to know something; everyone seems to do a large water change at least twice a week and I wanted to know the reason why. Is it just to get fresh water in there or is it because African Cichlids give off so much waste that it can cause ammonia spikes? Currently in my 75 gallon tank I have 14 fish but so far my ammonia and nitrate arent elevated. Should I only be doing water changes when I see a spike in readings?


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## Deeda (Oct 12, 2012)

The amount of water changes aquarists do can vary from tank to tank and often depends on stocking levels or just personal preference. Water changes help to remove unknown substances that we don't or can't test for.

You should not see ammonia or nitrite in a cycled tank unless you have changed something recently such as adding more fish, medicated for illness or were overly enthusiastic cleaning the filter.

Nitrate increase is often used by some to determine water change frequency and the often cited suggestion is to change when it reaches 20 PPM.


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## ken31cay (Oct 9, 2018)

Deeda said:


> Water changes help to remove unknown substances that we don't or can't test for. Nitrate increase is often used by some to determine water change frequency and the often cited suggestion is to change when it reaches 20 PPM.


+1 thank you, good information. Some refer to the unknown substances as 'docs' dissolved organics and Nitrate levels are an indication of water quality.


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## DJRansome (Oct 29, 2005)

I like the idea of doing weekly 50% as a minimum and only increasing percent and frequency if I can't keep my readings between 10ppm and 20ppm with that schedule.


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## punman (Oct 24, 2003)

I have a 90 gallon with 16 tropheus and I change about 60% every week. I suppose I could do 30% twice a week but just too lazy and the 60% seems fine. Some fish could be more sensitive and want smaller changes. Number and size of fish are factors but so is amount of food fed.


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