Daily water changes

[leslie]

What is the minimum percentage of water I will need to change daily if I am growing out 3-3.5" discus? Thanks.

[Jennie]

feed heavy and change out 90%.. If that isn't option, consider bigger fish

[Laconic]

90% a day is pretty high. Great for the fish but I would not consider this a minimum. The more you can change, the better. Its easy to change a large percentage in a small tank but if you have a 100G plus tank, doing 90% a day is a lot of work.

I think the water change post in the simplydiscus library is very good:
http://www.simplydiscus.com/library/..._formula.shtml

In short:
A 33% water change gives you about 2 days worth of waste as a constant.
A 25% WC gives you about 3 days of waste.
A 10% WC gives you about 9 days of waste.
A 1 - 2% WC (10% every week) gives you around 75 days of waste!

Notice the drastic increase from 10-25%. I try to do a 25-33% change daily with my 100G

[John_Nicholson]

It all depends on how you feed. It can be as low as 10% or as high as 100%. It is all about keeping your water clean. I normally do 50% 6 days a week.

Good luck.

-john

[Chad Hughes]

+1

It all depends on how you feed. It can be as low as 10% or as high as 100%. It is all about keeping your water clean. I normally do 50% 6 days a week.

Good luck.

-john

[Jhhnn]

I probably sound like a broken record, but you're really asking the wrong question, imo. A better question would be "How can I create a discus keeping system with water changing that's fast, safe, and easy?" There are lots of different ways to do that, depending on circumstance and ingenuity, but it's a key ingredient to long term success. Don't try to avoid it- try to make it low hassle with investment and planning.

Discus, particularly growing discus, require very good water quality to thrive. And youngsters require very large quantities of food if they're to grow to be big, beautiful discus. The two aren't incompatible, but it takes either a lot of water changing or adept use of advanced technology in tanks with relatively low populations of discus.

[discusviet]

I use river water instead of directly to 100% of fish daily. glass on the lake too. Healthy fish and eat a lot ... after 3 months of 6-7cm

[discusviet]

New members should not be allowed to send pictures .. Photos will be sent to you refer to

[ericatdallas]

90% a day is pretty high. Great for the fish but I would not consider this a minimum. The more you can change, the better. Its easy to change a large percentage in a small tank but if you have a 100G plus tank, doing 90% a day is a lot of work.

I think the water change post in the simplydiscus library is very good:
http://www.simplydiscus.com/library/..._formula.shtml

In short:
A 33% water change gives you about 2 days worth of waste as a constant.
A 25% WC gives you about 3 days of waste.
A 10% WC gives you about 9 days of waste.
A 1 - 2% WC (10% every week) gives you around 75 days of waste!

Notice the drastic increase from 10-25%. I try to do a 25-33% change daily with my 100G

I've seen this equation in another forum before and I don't really like it. The main reason is, I may change my water at 50% but that doesn't mean I -only- remove 50% of the waste. I have BB and I can vacuum out more than that. Even in my gravel tank, if I go directly to the bottom, I guarantee you I will grab more waste since waste sinks.

In the morning if I'm rushed, I'll do a 4G bucket WC (vacuuming debris from bottom), and that's only about a 5% WC. That's more efficient than 50% WC with siphon in the midway mark. In fact, I would say if you remove most of the waste on the bottom, the larger the water change will lead to diminishing returns (A 50% WC will not be twice as effective as a 25% WC and a 75% will definitely not be 3x more effective than a 25%).

Because the series (WC) do converge, it is a good indicator to tell you when you should do one big water change. For example, if you do a 33% WC (whether daily, weekly, or whenever), the amount of wastes converges to a certain amount after 10 days. So every 10 days (weeks, or whatever you schedule is - i.e. weekly water changes then do ONE BIG CHANGE every tenth week), you should consider doing a much greater water change or thorough cleaning. This doesn't take into account of planted tanks. I have a 75G planted that has zero nitrates, nitrites, and ammonia every time I test it. I still clean it once a week though to replenish nutrients and get rid of solid wastes.


^
| Change days to (time units). Time units being the schedule you use to change (so if you change water every 3d day, the series hits it's max at the number indicated x 3). The numbers are in units of (waste per day) regardless of WC schedule.

From the table, it shows the MAX waste accumulation (assuming perfect solution of waste in aquarium and uniform removal) and at what day it hits that max (approximate).

[Skip]

buaahhhh!!! eric you really like equations.!lol

[YSS]

How about also asking how many discus and tank size? All both very relevant info.

[Mxx]

Another good question to ask oneself might be, 'how can I remove metabolic fish waste continuously and immediately instead of having it accumulating constantly between (and in spite of) water changes and thus allowing it to build up to any levels which would hinder my discus'? Depending upon your open-mindedness, you could use such 'advanced technologies' as nitrifying and denitrifying bacteria and plants, (i.e. nature), to maximize your water quality, with a decent sized bio filter & nitrate filter, and/or plants (floating or otherwise).

You can then do water changes as you see fit, but you'd nevertheless be able to improve your water quality like this compared to water changes alone. But some might still see this is a ludicrous proposition I'm sure. Best of luck!

[Darrell Ward]

What is the minimum percentage of water I will need to change daily if I am growing out 3-3.5" discus? Thanks.

It depends on a lot of factors. For example, I've never had any problem growing out fish to adult size at 6 juvies per 55 gal. tank, with 2, 50 to 75% water changes weekly, feeding a lot of live food, and flake/mix 4 times daily, taking care not to let food sit around in the tank. With care, you don't have to make daily water changes to grow out fish without stunting them. It's a balance. As everyone develops their own methods over time, "your mileage may vary".

[Jhhnn]

It depends on a lot of factors. For example, I've never had any problem growing out fish to adult size at 6 juvies per 55 gal. tank, with 2, 50 to 75% water changes weekly, feeding a lot of live food, and flake/mix 4 times daily, taking care not to let food sit around in the tank. With care, you don't have to make daily water changes to grow out fish without stunting them. It's a balance. As everyone develops their own methods over time, "your mileage may vary".

Obviously, it's important for hobbyists who have a lot of tanks to optimize their efforts technologically and with judgment gained from experience. OTOH, it's important to realize and to emphasize the idea that the effects of doing too much are far preferable to the effects of not doing enough, and that our testkits give us a very narrow window into the community of life in the organic soup we call aquarium water. The effects of slowly deteriorating water quality are cumulative, and subtle, until the fish arrive in a crisis situation, at which point they can simply be too damaged to fully recover, regardless of the remedies applied. Best to stay well into the safe zone of water quality all along to avoid problems. For me, that's meant near daily water changes of 50% or more. It's never fallen below 5X/wk, never missed 2 days in a row. Can I get by on less? Probably, but I'm not interested in finding out just how much less.

I do have a fairly elaborate water aging and changing system, well worth the time, effort and money to set it up. Staying well into the safe zone of water quality is the second smartest thing I've done with discus. The first was buying healthy stock from Kenny, and I'm not sure I wasn't more lucky than good in making that choice at the time.

[leslie]

I appreciate all the comments and suggestions. I have a 65 gal tank with JBJ Reaction 4-Stage UV-45 canister filter (290gph) and sponge filter. I will have 8, 3" to 3.5" discus (have ordered them but will not receive them for a week or so). It was recommended to me that I do a 50% water change every other day based on my tank size, filtration and # of fish. I also plan to keep the tank clean of excess food and waste. The water going into the tank is the same as our tap water. My filter has been connected to the house plumbing. The outgoing water is bypassing the septic and going directly into the yard. Is there a # of degree temp change that the fish can handle? If I change 50% with water that is 2 degrees colder than the tank water will it harm the fish?