i wonder...

[SC Fish]

my first ever fish tank , my 10 gallon , home to 7 adult , 5 baby platys, 5 mountain minnows and 3 shrimps has been set up for 1 year and 8 months happily with no issues , no diseases, at all.  

my tank is also planted with live rock , black sand and drift wood.

i see videos of people with tank just 6 months old and they say doing water changes isn't necessary at that level and they simply top up the water when needed. Is this recommended and what if i where to do 1 water change a month and just top up? 

Also i see people claiming that adding plain tap water to a fish tank that is fully cycled is fine because the bacteria in the filter and what not will cure the tap water of impurities, is this true? and is this recommended?

[Flumpweesel]

First well done on what's sounds like a great start in fish keeping. Obviously what you are currently doing works.

I figure out my water changes by testing and only change (while gravel vaccing) when the test show nitrate gets higher than I like I aim to stay between 20 and 40ppm to keep the plants happy as well as the fish. This is roughly every 2 months for my tanks, tight lid mean they don't really need topping up in between but I occasionally steal water for the house plants.

I would suggest you adopt a similar process test your water at least weekly and change when the tests tell you to. If you want to reduce the number of water changes you do.

The main reason we condition water however is to remove chlorine which will not be removed by your filter. It can be gassed off but you really have to know what your dealing with to rely on that. Chlorine will harm your fish so to my mind never worth the risk of not adding a dechlorinator. 

The sad truth at the moment is that there is a lot of bad advice on line it may just be short sighted (they may use well water) but without knowing the chemical make up of the water source why take a risk.

[Flumpweesel]

I'll also add here that there are issues with topping up rather than water changing, when water in tanks evaporates it's only the H20 that evaporates it leaves behind any minerals, salts and  stuff and that can be an issue if you already have quite hard water. 

[Odd Duck]

To add to @Flumpweesel’s information, there are also substances in the water that are not tested for with any home test kit and would even be beyond nearly all commercial testing.  Water changes bring in fresh water, presumably usually cleaner than the tank water.  Nearly all municipalities will be adding either chlorine or chloramines (or both) to disinfect the water before it gets to your tap.  So dechlorinators are the general rule to be safe.

But the other compounds we don’t test for can accumulate with only water top offs, even if you use RO or other purified water.  So, yes, it’s possible to maintain a tank for a long time with water top offs, but it can get more complicated instead of easier to keep the fish healthy that way.  Water changes are not usually too difficult and are an easy way to maintain optimal water quality assuming your tap water is safe to drink.  Skipping water changes is definitely not recommended for beginners and not really a good idea even for most experienced aquarists.  I’ve been keeping fish since 1975 and will certainly admit to doing water changes less often than I would prefer (sometimes life gets in the way) but I don’t skip them entirely.  It’s just not worth it.  I don’t need bragging rights to “I haven’t done a water change in 6 months”.  I’d much rather have bragging rights to, “My fish are doing fantastic”.  I’m still a bit hit or miss on that one with some of the trickier species I’ve tried.

[nabokovfan87]

On 10/29/2022 at 3:26 AM, SC Fish said:

Also i see people claiming that adding plain tap water to a fish tank that is fully cycled is fine because the bacteria in the filter and what not will cure the tap water of impurities, is this true? and is this recommended?

Definitely not.... It all depends on the water.  The place I moved to the water company changes things every 3-4 months on us and it's never great.  They use water testing to track diseases and there's a lot of stuff in water besides water, depending on what that water goes through before it gets to you. 

Honestly, always use dechlorinator. Its cheap, safe, smart, and easy to do.

 

On 10/29/2022 at 6:00 AM, Flumpweesel said:

The main reason we condition water however is to remove chlorine which will not be removed by your filter. It can be gassed off but you really have to know what your dealing with to rely on that. Chlorine will harm your fish so to my mind never worth the risk of not adding a dechlorinator. 

Agreed. From the stuff I looked at you're talking up to 24 hours to off-gas chlorine, but chloramines can take much longer and usually get removed via sunlight in most cases.  As mentioned, we don't really know what goes on before the water gets to us, and so if you can't get that tested often, then you're best bet is to just use a few drops of dechlor and take some of the concerns out of the way very easily.

 

 

Edited October 30, 2022 by nabokovfan87

[SC Fish]

On 10/29/2022 at 8:01 PM, Flumpweesel said:

I'll also add here that there are issues with topping up rather than water changing, when water in tanks evaporates it's only the H20 that evaporates it leaves behind any minerals, salts and  stuff and that can be an issue if you already have quite hard water. 

 

On 10/29/2022 at 2:00 PM, Flumpweesel said:

First well done on what's sounds like a great start in fish keeping. Obviously what you are currently doing works.

I figure out my water changes by testing and only change (while gravel vaccing) when the test show nitrate gets higher than I like I aim to stay between 20 and 40ppm to keep the plants happy as well as the fish. This is roughly every 2 months for my tanks, tight lid mean they don't really need topping up in between but I occasionally steal water for the house plants.

I would suggest you adopt a similar process test your water at least weekly and change when the tests tell you to. If you want to reduce the number of water changes you do.

The main reason we condition water however is to remove chlorine which will not be removed by your filter. It can be gassed off but you really have to know what your dealing with to rely on that. Chlorine will harm your fish so to my mind never worth the risk of not adding a dechlorinator. 

The sad truth at the moment is that there is a lot of bad advice on line it may just be short sighted (they may use well water) but without knowing the chemical make up of the water source why take a risk.

hey! thanks for the feedback. and yeah i think i got off quite lucky for my start in the hobby. its just now with my new 20 gallon that my first issue has arised. fin rot. but I'm getting it treated which is why i didnt read your comment yesterday.  Also based on what you have said , i think ill just carry on water changing every week to 2 weeks and cleaning the sponge twice a month. as like you said, it clearly works . 

 

i also know both my tanks have very hard water. both tests show around 140 to 160 hardness. and actually when i first set up my 20 gallon the test showed 180! which was fine for the platys as they live in hard water anyways and in my 10 gallon they have for over 1.8 years

 

[Flumpweesel]

Good luck with the fin rot, it can be quite a journey I got a goldfish through with super clean water (treating without antibiotics in my case ).

 

[SC Fish]

On 10/30/2022 at 11:47 AM, Flumpweesel said:

Good luck with the fin rot, it can be quite a journey I got a goldfish through with super clean water (treating without antibiotics in my case ).

 

mine is with a few guppys, in a community tank (platys , neon tetras , fancy guppys and endlers.) and im using a treatment by interpret , "anti fungus & finrot+" it seems to have clouded my water up a bit but it says that that will happen and water changes are not recommended , so i need to put up with it for 6 more days and then water change but its fine , as it will help my fish

[B7gwap]

So it actually is as simple as mathematical addition and subtraction. 
You add fish food, it has in it nitrogen compounds that your fish turn into ammonia for your bacteria to turn into nitrite and nitrate, as you know. 
 

your plants consume that nitrogen, depending on the plant, how densely planted, light saturation, etc etc, but essentially when they grow, they are removing Nitrogen from your water. 
 

In order for the sum of this math problem to be zero, the nitrogen production needs to equal the nitrogen consumption. The way you can verify it is, as has been stated, testing for nitrogen. All this said, you absolutely can and should let plants live all over your tank, they will reduce your maintenance burden, look beautiful, and make your fish feel more at home. 
 

The top off question, once again, others have touched on it, but every time you add tap water you aren’t simply adding H2O. All the minerals and chlorine are also along for the ride. If you have livebearers or rainbows or African cichlids that love insanely hard water, you may get away with the minerals part, but nothing alive likes chlorine. You have to at least let it evaporate out of the tap water. ACO’s test strips are awesome for this because they include a chlorine test pad. Pour a 5 gallon bucket of tap water and check it. Then let it sit out for 24-48 hours and test it again. (Then do it with an air stone in there to see what it does) 

TL,DR: Topping off works best if you use RODI, have a massive plant to fish ratio, and test for Nitrogen regularly. But it can work. 

Edited October 30, 2022 by B7gwap

[Mitch_ScruffyCityAquatics]

I agree with what has been said. I don’t know that it is realistic to be at the point of no water changes in a new tank, but a fresh setup could be “jump started” by used filter media, used decorations, and lots of plants. Those who stop water changes early probably didn’t start with a fresh tank, filter, substrate, or decorations. They are probably very experienced and used stuff that was already covered in beneficial bacteria with lots of plants.