Water changw frequency

[Divinityinlove]

Recently I've learned on this forum that 50%-90% water changes even weekly suggested are good for clean aquarium water.

Considering most things I've seen (and still see outside this new information on this forum) recommend 10%-25% max weekly changes.. I have follow up questions about the water chemistry before I proceed to do bigger changes.

The main one is: My tap water being pretty hard, what if I want/need softer /more acidic water? I don't have an RO system yet... Not sure how long til I can financially and practically afford one.

Is leaving most of the water cycling better for the pH than weekly adding all those new minerals? My pH is usually 7.5 but last week I did a 50% water change and it is now 8. I can't have it any higher. So unsure how to bring it down again if I'm going to do another big change.

If this question can be answered please, I might add secondary questions but want to focus on this first.

Thanks a lot as always!

 

[Wills]

Hi weekly 50% water changes have massive benefits for our aquariums. For fish it not just removes nitrates (unless you have an other way of reducing these) but also hormones and other chemicals produced by the fish waste over time.

10-25% wont do too much. Think about if your tank was filled with bright blue dye how much would you have to change before it made a difference?

Have you tested your tap water in terms of hardness and ph? You can do this two ways, first straight from the tap and an other leave a sample for 24 hours and test again. In terms of your water being a lower ph in the tank is there a reason for this - eg do you have loads of wood, any botanicals like leaves or seed pods etc? Sometimes aquarium soil can soften water too if you are using that?

Wills

 

[Back in the fold]

Throughout most of my years keeping fish in aquariums I was haphazard and lackadaisical about water changes. I would let my tanks go for , sometimes , weeks and then go on a binge and do water changes profusely . I can tell you from my own experience that's not a recipe for success. Now that I am retired I have time to devote to this and do things right. I have not missed a weekly 50% water change in over two years now. Working people with family obligations may find this difficult as it is time consuming but it must be done. As you would do with any pet do for your fish. You walk your dog and clean up after him , you clean your birds cage and you empty your cat dirt. Fish need this regular care as well. Since I've made this effort to do my regular water changes I see the results. My fish are healthy and breed regularly. I also have extremely low fish death. Out of about 100 fish I've lost three in the past two years.

 

[Rocky998]

For my fry tank I do about 60-90% water changes weekly. For my main tank I do 25-60% water changes weekly. (I always try to do a 50-60% on my main tank when possible)

 

[GaryE]

The only reliable way to soften your water is RO, unless you move to a rainforest. I don't know how good London rainwater would be, or even how reliable.
So you're basically stuck with those water values, unless you spend and buy RO. That discourages water changing, as all the carrying etc becomes a chore.
A roller coaster isn't going to be a good idea. You want stability, and the techniques and products to acidify water don't give you that.
I battled this issue for 10 years at one point, and ended up shifting to hardwater evolved species and just enjoying the water I had. I tend to change 25-30% weekly, but do more for fry tanks, or if I have a lot of free time.

 

[Essjay]

London tap water is usually described as liquid rock. It is very hard. The only way to reduce it as Gary said is mixing it with RO to get the hardness you want, then use the same mixture at every water change. I wouldn't use rainwater in a city as large as London with all the pollution a large city creates.

 

[Valkyrie_Lips]

I can guarantee that other fish forums also have a plethora of people who do larger weekly water changes because the proof is in the pudding. They keep fish healthier and minimize the risk of sickness. Why do you think one of the go-to treatments for sick/injured fish is increased water changes? The clean water helps promote healing and it reduces the risk of infection without the stress of medication.

As for the lower pH in your tank high nitrates can also lower the pH. Small water changes will not remove much nitrates so they can accumulate rather quickly if one if adverse to larger water changes. If that's the case once you bring them down your tank will stabilize and your source water should match the tank pH.

 

[Divinityinlove]

Hi weekly 50% water changes have massive benefits for our aquariums. For fish it not just removes nitrates (unless you have an other way of reducing these) but also hormones and other chemicals produced by the fish waste over time.

10-25% wont do too much. Think about if your tank was filled with bright blue dye how much would you have to change before it made a difference?

Have you tested your tap water in terms of hardness and ph? You can do this two ways, first straight from the tap and an other leave a sample for 24 hours and test again. In terms of your water being a lower ph in the tank is there a reason for this - eg do you have loads of wood, any botanicals like leaves or seed pods etc? Sometimes aquarium soil can soften water too if you are using that?

Wills

The water in my tank had lower pH because I was doing only 20% WC weekly so the water was acidic with the decomposition. Now I'm doing 50% weekly and the pH is higher because I guest the minerals in new water make it pH higher?

 

[Divinityinlove]

London tap water is usually described as liquid rock. It is very hard. The only way to reduce it as Gary said is mixing it with RO to get the hardness you want, then use the same mixture at every water change. I wouldn't use rainwater in a city as large as London with all the pollution a large city creates.

When I measure gh and kh tho on the strips it is always in an OK (green, safe) level. I also watched a yt video yesterday saying hard water is good for plants? I now don't really understand why I need to soften water. Any good articles or videos to understand more?

 

[Divinityinlove]

I can guarantee that other fish forums like FishLore also have a plethora of people who do larger weekly water changes because the proof is in the pudding. They keep fish healthier and minimize the risk of sickness. Why do you think one of the go-to treatments for sick/injured fish is increased water changes? The clean water helps promote healing and it reduces the risk of infection without the stress of medication.

As for the lower pH in your tank high nitrates can also lower the pH. Small water changes will not remove much nitrates so they can accumulate rather quickly if one if adverse to larger water changes. If that's the case once you bring them down your tank will stabilize and your source water should match the tank pH.

I'm confused. So, I now do 50% water changes and my pH is 8.
But I want my pH to be 7.5 maximum. So I had better pH when doing only 25% WC. My concern is if I keep doing 50% WC, will it go higher?? Because I read above 8 is dangerous.

 

[AmyKieran]

I'm confused. So, I now do 50% water changes and my pH is 8.
But I want my pH to be 7.5 maximum. So I had better pH when doing only 25% WC. My concern is if I keep doing 50% WC, will it go higher?? Because I read above 8 is dangerous.

Your ph will only stay what your tap water is, albeit a little out sometimes. If you wanted to lower ph you could try almond leaves

 

[Divinityinlove]

Your ph will only stay what your tap water is, albeit a little out sometimes. If you wanted to lower ph you could try almond leaves

Yes I have almond leaves in the tank. I can add more of then for now.

 

[AmyKieran]

Yes I have almond leaves in the tank. I can add more of then for now.

Okay, what fish are you looking to keep? Your high ph and water hardness would be great for rift lake cichlids

 

[Essjay]

When I measure gh and kh tho on the strips it is always in an OK (green, safe) level.

There is no such thing as 'safe' GH and KH despite what the tester says. Things like ammonia, nitrite and nitrate can harm fish if there is too much in the water, any type of water, but GH only harms fish if it is significantly different from the type of water in which any given species lives in the wild. And KH only affects fish in it's ability to stabilise pH. When KH is very low, there is a risk that pH can drop a lot very suddenly, which is not good for fish. If it's high and the fishkeeper adds pH lowering chemicals, the pH will drop then bounce back and this yoyoing is not good for fish.

Some test strips only measure as high as 180 ppm GH. It could be exactly 180 ppm or anything higher and still read 180.


Have you looked on your water company's website for hardness?

 

[GaryE]

If you're one of those poor souls who don't "believe in" evolution, this won't help. But there are no rules in fishkeeping other than that fish and plants are diverse, and what works for one, water-wise, may not work for another. There are many fish that have adapted to very hard water, and would thrive in your tanks.
pH is easy to read, but deceptive. It tends to be higher if there are a lot of minerals in the water. Tends. Again, that isn't set in stone (accidental pun there).
It's often a matter of looking at where the fish originates, and then at a map. Coastal species tend to need harder water, as limestone and dead coral are common along coasts. Rainforests have very soft water. I live along the Atlantic coast of Canada, and tested a local lake this morning - very soft and acidic. So we're talking tendencies. In coastal Mexico, relatively recently risen out of the sea, the pH is very high and the water very hard.

We want rules or laws. They just don't work here. Your pH will tend to be what comes from the tap, and almond leaves release tannins and will affect pH in poorly buffered water, but are truly useless except in a cosmetic way. They won't change the minerals, and they are what matter to the fish and plants.