# Water change in a heavy planted tank



## arc (Mar 11, 2010)

Question to those with heavily planted tanks, how often do you do water changes? 

I've always followed the 10-20% water change per week but since converting to a planted tank and testing for nitrates, I've scaled it back to 20-25 once every 2-3 weeks. The API tests always show 0 for nitrates which got me worried so I tested it on some KNO3 solution I had. The API showed 140+ for the KNO3 so they are working. 

Does this mean I can scale back water changes to 1 month or even more?

My bio load isn't small either, I'm positive I'm overstocked since there is over 30 fishes in a 29 gallon tank.


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## GuppiesAndBetta (Jul 27, 2009)

If it is a heavily planted tank, it is not unusual for nitrates to show up as 0, especially if it has been established and is stable for a while.


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## Mr Fishies (Sep 21, 2007)

For keeping your plants healthy, water changes can be a good thing. Along with the Nitrates that may read 0 all the time, there are other elements that the plants use up that can/will eventually hinder plant growth.

Water added during changes provide a source of minerals associated with GH/KH readings (Ca and Mg) for example, if you slow down or stop water changes, you may also notice these parameters drop gradually. Once anything a plant wants to use up is gone, or too low to effectively remove more from the water, it will affect growth.

I've kept soil based El Natural style tanks, the biggest was 50G, that I did 25% water changes on once every 3-4 months. For 4-5 years (until they were moved to a 75G), fish were healthy and plants were growing, but everything always seemed happier after a eater change, plants grew a bit faster for a while etc.

A healthy heavily planted tank allows you a lot more leeway between changes, for sure. But if water changes are easy for you (have a good system, hoses, pumps, python etc), there are very few arguments against doing them as frequently as you like. I'd say pushing to 3 weeks as a matter of practice is using your leeway up - so a missed change or vacation can have a more profound impact. If 25% a week is no hassle to you and you want to, go for it. I change 50% a week.


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## Philip.Chan.92 (Apr 25, 2010)

Even if you are heavily planted, it's good to keep up with weekly changes but instead of a 25% water chance you can get away with 15% since the plants DO absorb a lot of nitrates. If you have sensitive fish then it's best to do 25% water changes.


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## mauve (Apr 12, 2010)

I have 2 heavily planted tanks (5 and 25g) and I just partially change water very rarely, once 2 months or ever more seldom. Lo tech approach, although I do add CO2 with great results. 
Most of the time I just add rain water collecting in a tub on my balcony.
Fish and plants are very happy...


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## Philip.Chan.92 (Apr 25, 2010)

Rain water in Toronto isn't clean, it has tons of dust and pollution particles that can be toxic to fish. A water change once every two months is not recommended, it may work out for you but most people cannot get away with that.


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## NVES (Apr 21, 2010)

What defines a heavily planted tank?


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## mauve (Apr 12, 2010)

Philip.Chan.92 said:


> A water change once every two months is not recommended, it may work out for you but most people cannot get away with that.


Thank God I don't belong to the "most people" category. 
Here is an amazing site where a lot is explained.
http://www.malloftheworld.com/aquarium/part2.htm


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## Mr Fishies (Sep 21, 2007)

NVES said:


> What defines a heavily planted tank?


IMO: A tank where 50% or more of the volume is filled with plant. If you look from the front and see little or no background and/or if you look from the top you see little or no substrate.

That said, a tank with nothing but a carpet of HC on the bottom is not really heavily planted since the plant mass of a 1-2" tall carpet is quite small.

Some may argue with my choices, but the following (both are 300l tanks in the latest AGA contest) that seem like good examples:

This one is:







This one isnt:


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## Harry Muscle (Mar 21, 2007)

Talking about water changes in planted tank, it's probably worth while reading Tom Barr's take on this. It's located here: http://www.barrreport.com/showthread.php/433-Non-CO2-methods . I've followed his method with my 55G tank and did water changes every two months or so and things worked out great.

Harry


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## arc (Mar 11, 2010)

My tank would be somewhere inbetween the examples Mr Fishies has. Lots of background plants but low on the carpeting plants. I've got a fair amount of tetras/cories so trying not to reduce their swimming space.



> I have 2 heavily planted tanks (5 and 25g) and I just partially change water very rarely, once 2 months or ever more seldom. Lo tech approach, although I do add CO2 with great results.


What kind of fish do you have?



> Talking about water changes in planted tank, it's probably worth while reading Tom Barr's take on this. It's located here: http://www.barrreport.com/showthread...on-CO2-methods . I've followed his method with my 55G tank and did water changes every two months or so and things worked out great.


Great read! I think I've been accidentally doing the non-Co2 method since I've got moderate WPG(2), no CO2 and been dosing with small amounts of trace mixture and KNO3. plants are not growing fast but are growing and the fish are happy (bright colours, active and hungry) 2 months between water changes...this one I'm afraid of though


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## mauve (Apr 12, 2010)

arc said:


> What kind of fish do you have?


In 25g I have 2 rams, 2 neons and 1 algae eater so far.
The 5 g has a bunch of guppies, 2 sword tails, 2 algae eaters.


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## KhuliLoachFan (Mar 8, 2008)

Nitrates, as the final compound in the nitrogen cycle, are the most understood, and "visible" thing to the hobbyist, but are a bit of a "stand-in" for total water pollution, in our mental model. Once your nitrates are not accumulating you can no longer use them to gauge your water changes. In my planted tanks, I still get nitrate accumulation, I think because I have a low-tech no-co2 system and therefore, the fish bioload is still greater than the absorbing capability of my plants. I wonder, if you shouldn't switch to mostly checking your pH stability, and forget about checking nitrates regularly if they are always 0.

W


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## arc (Mar 11, 2010)

I test ph, A, Ni, Na about twice a week since I'm overdue for a waterchange right now. I'll have to get a GH/KH testkit in the future.


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## KhuliLoachFan (Mar 8, 2008)

No worries then. You're way on top of it.

W


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## golfers1 (May 17, 2006)

Well, there isn't much to add, but it is important to think of the fish in this way. If you were stuck in a confined space that's maybe over crowded, how would you feel? Interesting isn't it.
My 55G has 4 Dwarf Rainbow(2"), 15 Cardinal Tetras(1"), 18 Rasbora's(1.5"), 4cory's (2"), 2 Otto's(2"), 1 Pleco (2"), 1 Show Betta(FireTail). Full of plants(Heavy). Co2 infuzed (Solenoid). UPS. High Tech Tank(it's all set on Timers).
I could leave it for a month if I needed too, with the UPS I can be worry free. 
I change 15-25% of their water every 4-7 days, I don't worry about nitrite's with the plants and Bioload(Fluval 305 is changed every 3 months), as I siphion off just a little bit of the top layer of waste each time I do a change. Fish are used to it now and try biting my fingers when I'm in there(This is a good sign they acknowledge who I am). I down cut alot of plants at this time too, I can't get rid of them fast enough (If you want alot of plants cheap come see me). This also acclimatizes your fish to the tap water or rain water(this can be dangerous) or whatever you want to do. 
As you can see everyone has a different opinion/way they take care of their fish. So what you have to do is read about the types of fish you have and their reactions to their environment. This is why I'm not a big supporter of multiple/community tanks which have everything from cory's to guppies to platy's to tiger's to well everything, then they add a new species and they seem to die out due to water parameters. So, all in all pick your tank mates carefully and the type of tank you want to care for, then your can do more for your pets. I call them my kids. 
cheers


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