Why am I changing water?

Most low tech aquariums don't change their water often, only several times a year. You can check out several of these at natural aquarium dot com.

This only works on low tech, heavy planted tanks, with low stock.

To answer your question, water changes is not necessary if you have a balance.

You can likely tell I have read "The Ecology of the Planted Aquarium". My ten gallon is a no tech approach with soil.
 
just out of curiosity, is there a reason why you have chosen not to have a filter on the tank?

I have a bunch of Amano Shrimp in the tank and they tend to get caught in the filter. I also wanted to have more control over the surface disruptions than a HOB filter would provide. I live in an apartment and I would get in really big trouble if a canaster filter pumped all of my water on the floor so I have been leary of a canister.

Since I took it off I have noticed I have faster plant growth and no other problems. I think I am keeping more CO2 in solution from my DIY setup.
 
Not so much TDS as DOC - Dissolved Organic Compounds.

This, I think is important and I know very little about it. My test for DOC is to smell the water. I figure if it is organic it will smell. It looks like I need to address two hanging questions:

1. What is the fate of the elements needed to sustaian plant growth as fish food is degraded in the system.

2. What is the source and method of removal for DOCs.

I'll work on these concepts over the next few weeks.
 
This, I think is important and I know very little about it. My test for DOC is to smell the water. I figure if it is organic it will smell. It looks like I need to address two hanging questions:

1. What is the fate of the elements needed to sustaian plant growth as fish food is degraded in the system.

2. What is the source and method of removal for DOCs.

I'll work on these concepts over the next few weeks.

1 i dont get your question
2 water changes

Most low tech aquariums don't change their water often, only several times a year. You can check out several of these at natural aquarium dot com.

This only works on low tech, heavy planted tanks, with low stock.

To answer your question, water changes is not necessary if you have a balance.
i wouldnt say that at all. some people dont change their water. its a wasteland method where its plants first fish 2nd. low bio loads with lots of plants. yes some people do it but i believe its a very small percent.
 
Water changes are to keep the tank clean. It is understandable as to why you are wondering when you have been doing 2 a week. Most of us do between 25-50% weekly, your fish must love you for 33% twice weekly lol. The only time i change water twice a week is if i have a tank with loads of fry in.
 
These minerals are also not leaving the tank.

They aren't leaving the tank, but aren't they being taken up by your plants? If the plants don't have the minerals they need, wouldn't that slow their growth and therefore the rate at which they take up nitrogen and CO2 and put out oxygen and all that other great stuff they do? I suppose fertilizers would get around that...

My understanding is that you certainly can have a system that requires few water changes (but not zero---even a marsh gets fresh water via rain). You just have to recreate a natural system, and natural systems tend to be MUCH less densely populated than we typically want our tanks to be.
 
If you have low stocking but heavily planted, then I could see doing less water changes, maybe lessen to monthly. But, if you are heavily planted and heavily stocked, weekly or twice weekly is certainly needed to remove the waste, etc, that we can't measure. There are many things that are being released into the water by fish, inverts, and even plants that we don't necessarily know about or have the capacity to measure in the home aquarium (I can't speak for pros).

If you only have a planted aquarium, not stocked with fish or inverts, then I could see just topping up the water every now and again and maybe doing only a few WCs a year.
 
if you use the gravel vac to clean the gravel you will be doing water changes.;)
DOC is the big concern.

I believe that balances are made with natural tanks..
heavy planted , low stock and you can get away with longer intervals between water changes.
use ro/di for top offs you should(in theory) be fine.

there is plenty of documentation of natural tanks and they seem to work out fine.. again.it is finding the balance.


you're not too far off base(IMO)
 
I do water changes to allow me to reset the tank and dose nutrients without having to use a test kit, which I suspect no one here has calibrated theirs..............so they do not do much good for things like NO3, PO4 unless you do.........

That's why pH meters use a two or three point reference.



Non CO2 planted tanks work quite well, depends on the goal however.
Many want a moderate to fast growth and easy to care for, be able to grow most any species etc.
I've yet to met any hobbyists that got into this to test and use test kits for water.

Have any of you ever met someone like that?
I have n't.

Water changes at say 50% allows you to avoid test kits altogether with as much accuracy , if not more.

If you dose say 20ppm every week of NO3 from KNO3, the max possible build up will 40ppm. It cannot ever go higher. Few tanks will use more than say 4ppm of NO3 per day, so that+ fish waste, you should be okay and never need a test kit.

So water chnges are tool to avoid test kits, keep the tank clean, helps getting in when it's 1/2 full and gardening the tank scape etc.

Plant tanks tend to pearl strongly after large water changes.

DOC are easy to deal with, ever heard of activated carbon?
hehe

Does it really help? Nope.

You can do this and many folks have, but no one I know has ever shown carbon does much other than remove organics and color.

TDS, well, plant growth and trimmings should export a lot of that. You can monitor which nutrients are adding to the TDS, some folks use that as a indicator for a water change.

Regards,
Tom Barr
 
AquariaCentral.com