topping up evaporated water: which chemicals can build up?

[Bubble_B0y]

Besides nitrate, I was wondering..

is there any other chemicals in the water that can become toxic over time?

[Jchillin]

Just a little confused about the title and the queation in your post.

Topping off evaported water will not add ammonia, nitrite or nitrate. Depending on how much water you are replacing, you can add dechlorinator to avoid build up of chlorine/chloramines.

[Tiffi]

I think he meant not actually changing water, but just add the amount of evaporated water back into the tank. So not taking any old water out.

[Bubble_B0y]

Originally Posted by Tiffi

I think he meant not actually changing water, but just add the amount of evaporated water back into the tank. So not taking any old water out.

yepp
what she said

[Zagz]

LOL, my water never has time to evaporate, I do too many pwc's for any substantial water to be added. But I do keep some treated water in a 5 gal pail so if I do need to top off every I have treated water ready. HTH.

[Tiffi]

You probably have canopy though, I have an open tank at this time, since my light fixture gave up on me (after 1 hour! $^&##!).
So right now I have quite a bit of evaporating water too.

[Zagz]

One of my tanks has a canopy but none of my tanks have open tops. I have 6 cats! Open top tanks would be a fishing hayday for the cats! 8O

[Jchillin]

Originally Posted by Jchillin

Just a little confused about the title and the queation in your post.

Topping off evaported water will not add ammonia, nitrite or nitrate. Depending on how much water you are replacing, you can add dechlorinator to avoid build up of chlorine/chloramines.

That's what I said as well.

[TomK2]

products of decay will accumulate in the tank. Not all substances end up as water, co2, or ammonia. Buffers will be depleted, as nitrification and decay are acidic processes. Various organic compounds will accumulate, often referred to as DOC for dissolved organic compounds. How much, and how significant they will be is hard to tell, and It would likely take months of no water changes or gravel vacs to see an obvious sign. Unfortunately, that obvious sign could be a pH crash or rash of ill health in your fish.

As for what the exact chemicals are, I can not say.

mostly if you just top off water and dont do water changes, you have a buildup of nitrates, not ammonia or nitrite. You can also get "old tank syndrome" which is a buildup of not only the nitrates, but old dechlor chemicals and stuff that you just keep adding

[BrianNY]

Both TomK2 and AshleyNichol are correct. In a closed and incomplete (without plants), ecosystem, a build up of nitrates and DOCs will occur. You must remember that nitrates are the final waste product of nitrifying bacteria. Without something such as pwcs and or plants to flush the system, they must build up.

The problem with DOCs in the water column is that they serve as a breeding ground for other more harmful bacteria. The more DOCs in the water, the more likely your fish will become ill. IMO adaquate pwcs are essential for maintaining a healthy aquatic environment.

[malkore]

In addition, hardness will build up , and it doesn't take long.

About 2 months of not changing water, just topping off a 20gallon...I went from tap water hardness of 9dKh and 13dGh to 14dKh and 18dGh. The tetra in the tank were not impressed at all.

Once you hit that point, you can't do huge water changes to fix it or the fish get stressed by the sudden drastic change in hardness (and pH).

Water changes are very much a regular duty to fishkeeping...much like taking your dog out to go poop, or scooping the kitty litter. Its not glamorous, but its part of the responsibility you agreed to when you accepted the pet.

[Bubble_B0y]

Originally Posted by malkore

In addition, hardness will build up , and it doesn't take long.

About 2 months of not changing water, just topping off a 20gallon...I went from tap water hardness of 9dKh and 13dGh to 14dKh and 18dGh. The tetra in the tank were not impressed at all.

confused - the Hardness stabilises the pH and prevents it from fluctuations.
Isn't this a good thing??

[Bubble_B0y]

what are DOC (dissolved organic compounds) and how do they affect the fish?

if you don't want to do PWC then you shouldn't keep fish, just the nitrates should be enough for you to know that it is a necessety, the fact that you are asking these questions makes it seem like you are too lazy to do the water changes and are trying to look for a loophole.
Ok, how would you like to live in a house and let your waste just build up, and build up, and build up, and never clean anything out?

[mrcrazypants05]

AshleyNicole... I've noticed that you attack people a lot. Makes me uncomfortable anytime I look into a topic and see you posted in it. Anyway... Not doing PWC makes a tank into what I've been told Old Tank Syndrome... Hard to introduce any new species into the tank because of all the chemicals adding up over time... because your fish have slowly acclimated to the gradual increments... not a good idea... My friends mom does that with her tank... just tops it off. Not sure when the last time they changed their water was... I'll have to introduce them to the python and give them some free dechlor just to get them to do it maybe lol.

[Jchillin]

I believe that the original question asked was about adding back evaporated water and had nothing at all to do with the member's desire to not do water changes.

Let's try to keep the thread on topic.

[malkore]

Originally Posted by Bubble_B0y

confused - the Hardness stabilises the pH and prevents it from fluctuations.
Isn't this a good thing??

Not necessarily. many fish live in soft water. a high carbonate and general hardness won't be to their liking. And carbonate hardness not only stabilizes pH, but also raises pH as it rises...because the carbonate hardness is a measure of alkalinity, and alkaline substances have a pH above 7.0.

Originally Posted by Bubble_B0y

what are DOC (dissolved organic compounds) and how do they affect the fish?

DOC's are the organic substances that do NOT break down in the aquarium...they simply build up.
Ever go to a pond that has no inlet and outlet for water? Notice how it smells kinda funky...and the water isn't very appealing to want to swim in?
Compare that to a small body of water that does have and inlet and outlet. That exports the DOC's out as well as providing fresh water.

if protein skimming worked for freshwater, it would help remove a lot of DOC's so our water changes could be smaller. However, skimming in FW is very inefficient, when it works at all, so we are left with PWC's as our only solution.

[Bubble_B0y]

Originally Posted by Jchillin

I believe that the original question asked was about adding back evaporated water and had nothing at all to do with the member's desire to not do water changes.

Let's try to keep the thread on topic.

yes
I didn't want to upset anyone.

I was just curious.
Naturally i'm a very inqusitive person and enjoy doing 'deep research' when puzzled about something.
I had no intention of becoming complacent with my water changes.

I have been keeping fish successfully for several years.
But when you regularly visit forums/messageboards, you become interested in the hobby (well for me anyway), to the extent that you MUST know EVERYTHING to the most extreme detail.
It's a great way of learning and it certainly doesn't hurt to know more than the basics and a little extra.

back to my original question:
I already knew about the nitrates building up over time.
However, I just needed justification, considering nitrates are kept to a minimum in planted tanks - which explains the additional questions.

[Bubble_B0y]

Originally Posted by malkore

Not necessarily. many fish live in soft water. a high carbonate and general hardness won't be to their liking. And carbonate hardness not only stabilizes pH, but also raises pH as it rises...because the carbonate hardness is a measure of alkalinity, and alkaline substances have a pH above 7.0.

DOC's are the organic substances that do NOT break down in the aquarium...they simply build up.
Ever go to a pond that has no inlet and outlet for water? Notice how it smells kinda funky...and the water isn't very appealing to want to swim in?
Compare that to a small body of water that does have and inlet and outlet. That exports the DOC's out as well as providing fresh water.

if protein skimming worked for freshwater, it would help remove a lot of DOC's so our water changes could be smaller. However, skimming in FW is very inefficient, when it works at all, so we are left with PWC's as our only solution.

thank-you very much.
This totally answers all my questions.
My perspective on water changes is completely justified.
I can now share this extra knowledge (if need be)

*we learn something new everyday in this hobby*