20 Gallon Tank Water Change Frequency in a Planted Tank

kreuztraeger

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I have one 3.5" goldfish in my 20 gallon tank with an Amazon Sword plant, and I'm wondering if I could change the water any less often than I would if I did not have the Amazon Sword.

I should change about 25% every week according to traditional advice, right? Could I change that to 10%, or maybe 25% a month?
 

Nutter

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Stick to your original water change shedule. The minerals introduced during water changes are not only important for your fish but also for the plant/s. One plant is not going to make an appreciable difference to how quickly pollutants build up in the water.
 

sik80

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one amazon sword won't make much difference. putting more plants in can reduce the need to water change as the plants can use some of the ammonia produced by fish for their growth. Wisteria (hygrophilla difformis) is good for this
 

Meenu

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sik80 said:
one amazon sword won't make much difference. putting more plants in can reduce the need to water change as the plants can use some of the ammonia produced by fish for their growth. Wisteria (hygrophilla difformis) is good for this
I would respectfully disagree with this. While it is true that live plants process toxins, they won't replenish necessary minerals. Also, over time, pH drops, and changing the water keeps it steadier. Even if every inch of your substrate were covered up with plants, I would still recommend frequent and regular water changes.
 

Nutter

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sik80 said:
one amazon sword won't make much difference. putting more plants in can reduce the need to water change as the plants can use some of the ammonia produced by fish for their growth. Wisteria (hygrophilla difformis) is good for this
Sorry but I have to disagree with that sik80. While plants do consume large amounts of ammonia & to a lesser extent nitrite & nitrate, that does not mean that less frequent water changes can be performed. That is a popular myth based on bad logic. Both fish & plants rely on the minerals present in the water for their continued good health. In aquariums that receive little or no added fertilizers, reducing the frequency of water changes also limits how much of those minerals are present for the plants to take up as nutrients. That can affect the plant health, which effects it's growth, which effects it's uptake of ammonia. If taken to extremes, the plants can eventually die & in fact add to the pollutants in the water.
 

sik80

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haha, I bow down to ur superior knowledge guys!

One of the reasons I said this was because of reading on another forum about a heavily planted, low stocked tank that hadn't had the water changed for 6 months. I think there was a soil substrate, which I guess helped to supply the trace nutrients over a long period.
 

Nutter

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sik80 said:
haha, I bow down to ur superior knowledge guys!

One of the reasons I said this was because of reading on another forum about a heavily planted, low stocked tank that hadn't had the water changed for 6 months. I think there was a soil substrate, which I guess helped to supply the trace nutrients over a long period.
Yeah you see storys like that occasionally but it is by no means the best way to go. Unfortunately those people don't always have the best interests of their fish at heart. Normally there is no mention in any of those stories how many of the plants have had to be replaced over the tanks life either. Even when using fertilizers it's best to do weekly water changes to keep the supply of minerals & micro organisms up for the plants. There's plenty of stuff in well & tap water that isn't present in most plant fertilizers.
 

TedsTank

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Well yes, a heavily planted tank and low stock could achieve a balance to mostly support itsef....but what is not mentioned is there are still water changes...if nothing but to replace evaporation...and usually ends up being a bit more. They balanced in that there are no filters, airstones etc.....I've seen it and it works....low stock is one of the key elements. The one I saw was full of valisneria (sp) and had about 4 or 5 native female mosquito fish. I can remember it running at least 5 years. Indirect sunlight. and office lights during the day.

With a goldfish a balance would probably never last...while all is well it would grow fast and then trash your balance and become stunted.
 

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