Question on water change

[Gemma]

I was wondering .... doing water changes, is it best to first drain the water and then replace it, or have running water going into the pond on one end, while pumping water out on the other end?

I understand that doing it the second way gives no idea of the percentage of water exchanged, but I'm a bit concerned over the period of time that I have to keep the waterfalls off and the liner dry, when I take all the water out and then refill

 

[MitchM]

What is the purpose of a water change?
(loaded question) I hope you don't mind.

 

[DutchMuch]

What is the purpose of a water change?
(loaded question) I hope you don't mind.

removes excess nutrients, possible ammonia nitrites nitrates, etc. And bacteria in the water, overall makes water cleaner and clearer for a temporary amount of time depending on your water change schedule. Water changes also temporarily put oxygen or up oxygen levels in the water. Water changes do make your fish more happy to for the time being, all the nice clean cool water. Same with plants you will notice all your submerged plants false pearling during a water change.

 

[DutchMuch]

I was wondering .... doing water changes, is it best to first drain the water and then replace it, or have running water going into the pond on one end, while pumping water out on the other end?

no, take out 50% or so, and refill it separate times.

 

[MitchM]

removes excess nutrients, possible ammonia nitrites nitrates, etc. And bacteria in the water, overall makes water cleaner and clearer for a temporary amount of time depending on your water change schedule. Water changes also temporarily put oxygen or up oxygen levels in the water. Water changes do make your fish more happy to for the time being, all the nice clean cool water. Same with plants you will notice all your submerged plants false pearling during a water change.

Can you explain:
Why are there excess nutrients in the first place?
Why do you need to remove bacteria?
How is clearer water - better? Is not a certain level of humic substances actually healthier for both fish and plants?
The other factors you mentioned are subjective, are they not? (happy fish, happy plants)

 

[Meyer Jordan]

What is the purpose of a water change?
(loaded question) I hope you don't mind.

Same question here. In many cases it is more deleterious to a pond than efficacious.
A small water change will give 'small', ineffective results. A large water change totally disrupts whatever ecological balance the pond may possess and it is a stressor for the fish. What many perceive as a 'happy' reaction from fish are really observing reaction to stress.
Water changes may be periodically essential to some aquaria, but are, except in pollutant-related emergencies, totally non-essential or even beneficial to ponds.

 

[DutchMuch]

Why are there excess nutrients in the first place?
Why do you need to remove bacteria?
How is clearer water - better? Is not a certain level of humic substances actually healthier for both fish and plants?
The other factors you mentioned are subjective, are they not? (happy fish, happy plants)

I'm 16 I don't know these huge words mean "subjective"
ill go from first to last question
Bad bacteria, possibly bad bacteria, removing bacteria isn't a bad thing and its not necessarily a good thing you just bluntly remove it. bacteria renews very quickly weather its beneficial or not, depending on "what" bacteria we are talking about.
Idk what the second part of what you said means mr. mad scientist. Clearer water isn't better, I didn't say that did I? no. I said it makes your water nice and clear. Clear water isn't bad either. It has its cons and pros. Like everything else. and Pros out ways the cons.

 

[DutchMuch]

it is a stressor for the fish

Sorry meyer, I highly disagree. maybe if your waving a huge tube around the water and chasing the fish with it, itll be stressful. A water change like Regular. Is not stressful but is the exact opposite.

 

[Gemma]

What is the purpose of a water change?
(loaded question) I hope you don't mind.

Just regular maintenance I change about 20% every 2 or 3 weeks

no, take out 50% or so, and refill it separate times.

50% would be 1,500gls, I thing it's a bit much not to mention it would take me hours to refill

 

[Meyer Jordan]

A water change like Regular. Is not stressful but is the exact opposite.

Do you have any data to support that statement?

 

[Gemma]

Water changes may be periodically essential to some aquaria, but are, except in pollutant-related emergencies, totally non-essential or even beneficial to ponds.

I thought regular water changes are recommended for fish health,by all pond experts, I guess I was wrong!

 

[MitchM]

I'm 16 I don't know these huge words mean "subjective"
ill go from first to last question
Bad bacteria, possibly bad bacteria, removing bacteria isn't a bad thing and its not necessarily a good thing you just bluntly remove it. bacteria renews very quickly weather its beneficial or not, depending on "what" bacteria we are talking about.
Idk what the second part of what you said means mr. mad scientist. Clearer water isn't better, I didn't say that did I? no. I said it makes your water nice and clear. Clear water isn't bad either. It has its cons and pros. Like everything else. and Pros out ways the cons.

Removing bacteria is a bad thing.
What you want is a healthy aquatic ecosystem that accommodates all bacteria at balanced levels. That can only be achieved by a stable environment where no bacteria is allowed to populate beyond a sustainable level.
What a water change does is reset the chemical parameters and requires bacteria populations to balance themselves out again.
That is called instability. Instability is not good for your fish.

You referred to happy fish, but how do you know they are happy? Is it because they are more active and darting around? That may be as a result from a water change and the fish are irritated as a result.
Whenever the chemical parameters of the water changes, the fishes osmoregulation must re equalize; see this:
https://en.wikipedia.org/wiki/Osmoregulation

Basically, the fish are irritated because of the water change.

I wish I was a mad scientist, then I could focus on what interests me and someone else could pay the bills.
(maybe I could ask my wife to dress up and get me a coffee and clean the test tubes, but I'm not brave enough to request that)

I know you follow Tom Barr, but he focuses on plant growth and colouration, not aquatic ecosystem health.

.

 

[Tula]

@Gemma , This is the first year I've pumped water out of the pond, but it's necessary as part of back washing our filter. In previous years I just topped off the pond and sometimes let it over flow. Now mind you, I don't have lots of plants due to the design of my pond and koi, but I believe my water is clearer ( I understand not necessarily better ) with this method.

 

[Gemma]

I didn't mean to start a debate over pros and cons of water changes! I just wanted to know the best method when I (for whatever reason) do a partial water change

@Tula My filter doesn't back flush, I just rinse the Media pad, and my plants are all on the upper section completely separate from the pond
How much water do you change and how long does it take you to refill the pond?

 

[MitchM]

I didn't mean to start a debate over pros and cons of water changes! I just wanted to know the best method when I (for whatever reason) do a partial water change
...

Sorry Gemma, I didn't mean to start a debate that's not wanted.
My answer (opinion) then, to your question, is to remove old water before you add new water for maximum effect of a water change.
My only advice would be to keep the water change percentage small and keep the new water parameters as close as possible to the old water parameters.