Water changes and filters

[boogie]

Hi. I have a question and want opinions/answers PLEASE.

I've read some really good threads here about PWC opinions.

I have always been told to do 20 -25% PWC per month by all my LFS's and books and here I am reading a lot of people stating that you should do up to 50% per week or more even.



What is the reason for this discrepancy?

Does having a lot of filtration help with any of this?

I grew up with LFS's stating that nitrates were not a health problem, yet now everything has changed dramatically where all the forums are saying that any nitrate at all is deadly, yet LFS's still state not to listen to the forums regarding Nitrates. I've even been told recently not to go on the forums from one of my LFS's, but that's not gonna happen, of course.

I do have a now overstocked fish tank 125 gallons with new plants and 6 fluval filters and one penquin with bio wheels - so there is a ton of filtration and water movement. Like I said, I have a lot of plants in 1/2 of my tank but I don't think they are doing anything - just there for interest. Read that sometimes plants really don't do anything for nitrates unless it is over planted with very few fish.

What are you guys' thoughts on this, please. There are so many drastically different opinions, but I really want all of your opinions on this.

Thank you for your time and interest.

 

[darkmule27]

There is likely confusion between nitrAte with nitrIte. NitrAte (NO3) is far less toxic to fish as it is a fairly stable, happy ion in water. NitrIte (NO2) is EXTREMELY toxic to fish and is much less stable. Only large concentrations of NO3 are dangerous to fish, but it's not a bad idea to keep them as low as possible. Plants will do little for nitrItes (NO2) because they cannot use it effectively, but they can use nitrAtes (and ammonia).

PWCs are partially personal preference and partially what the tank reuqires. I change 50% on a tank some people would likely only change 25%.
We (my mom and I) used to change 25% weekly until we realized that it's only 10 minutes more to change 50%. We also use a UGF, so the extra 25% allows us to REALLY vacuum the gravel well.

 

[cbwmn]

“I have always been told to do 20 -25% PWC per month by all my LFS's and books and here I am reading a lot of people stating that you should do up to 50% per week or more even.

What is the reason for this discrepancy?”

It’s not really a discrepancy.
A lot depends on the kind of fish you keep.
I keep dd black angels and they require good clean water.
Discus are in the same category. Most breeders change a high percentage of the tank water daily.
When my angels were under a year, I changed 50% daily and had no issues.
It’s also my opinion that most who work in LFS’s aren’t that well informed in aquatic requirements.
Most of them are trained to SELL.

“Does having a lot of filtration help with any of this?”
Yes, good filtration always helps, but some fish aren’t happy with a lot of water agitation.

I agree with darkmule on the NitrAte/NitrIte statement.
A lot also depends on how messy your fish are.
IMO – plants always help keep parameters in balance.
I test for NitrItes daily (and PH also).
I usually don’t check the other parameters as often because I do a lot of PWC’s.
It’s also important to check your water supply. If you have a water utility, they should have an analysis posted online.

Charles

 

[BillD]

If you want to know How often to change your water, get a nitrate test kit and keep tabs on it. The upper limit is generally considered 40ppm. I don't know where this number came from, but is probably a poor number to target for a number of reasons. A target of 20ppm or less would probably be more realistic as it would give you some leeway if you were to miss a change. The thing is that nitrate is used as an indicator of when to change as there are all sorts of other toxic compounds accumulating that we don't measure for. So, if it turns out that 25% weekly will keep your nitrates under 20ppm, that could be considered appropriate. However, if you were to change 50% weekly, that would only be beneficial, and give you more leeway.
If you are running on the edge, doing the bare minimum, you are taking a risk should something disrupt your water change schedule.
You can keep nitrate numbers lower by keeping filters clean; don't allow the solids to stay in the tank long enough to break down.
Lastly, it doesn't much matter how much filtration you have, the nitrate level will be determined by the bioload in the tank, not the number of filters or their type. In addition, every tank is unique and for anyone to tell you that an arbitrary number (%) is enough every (insert time factor) weeks/days/months, is improper. The real number can be determined by testing, but changing larger amounts than the minimum reduces risk and removes (virtually) the need for constant testing. Always better to err on changing "too much" than not enough. I trust that is of help. I will also say, that of all the very succcessful fish keepers/breeders I have met since joining an aquarium society, the one constant is that they all change large amounts of water regularly.
As far as pH goes, i ahven't tested for years, as it doesn't really matter what it is, the water I have is the water my fish will live in. They will adjust, or move on. having said that I have bred angels and tangs and killies in this water, and know a lot of people breeding a variety of fish, and none of them care much about pH.
I have to agree with the above post on the necessity of clean water for growing angels quickly and without defects.

 

[boogie]

Excellent answers and very thorough.

One more thing, if you don't mind.

I have read a lot on nitrates and it seems that the internet and books say it's very dangerous to have high levels, yet, the lfs - sellers, yes - say to me that I really shouldn't worry too much about it.

Can anyone really explain what the big deal is with nitrates if my nitrites are 0, my ammonia is 0 and my ph is perfect for both my fresh or salt tanks. I have never, ever, ever had low nitrates no matter what - ever! No matter how much I change my water it is still high and no - the nitrates are not high in my water supply as I have checked that numerous times. Yes, my bio load is extremely high, yet I am able to keep the 3 I mentioned above perfect.

Thanks for your input, it is extremely helpful in clarifying all my questions and doubts.

 

[underdog5004]

Nitrate seems to be the easiest for fish to live with, although "extremely" high levels are never awesome. I recommend lots of live plants. For fast growth in almost any condition, I recommend elodea (anacharis, goldfish grass) with hornwort coming in as a close second. These plants need very little light, and grow very quickly. I have live plants in my 10G and my 29G, and my nitrates are always under ~20ppm. If you're looking for a prettier plant, Java fern is kind of nice, and doesn't need a whole lot of light, although it does need a bit more than the other plants I mentioned.

PS - Not all of us LFS employees are numb-nut sell-sell-sell fish-pushers. Some of us care enough about the fish to tell people to cycle their tank for 3 weeks before coming in for fish, and some of us do read and study and learn as much as possible about keeping fish, to better serve our customers and our own tanks.

 

[BillD]

Perhaps we need to know what exactly "high" is in your case. If you changed 50% of your water, your nitrate level should drop by 50%; has to. If you are not staying ahead of the nitrates, you need to change more water. I change no less than 50%; frequency depends on the individual tank, but once a week is my target. When raising angel fry, I try to do daily changes of at least 50% to 60%.
As I mentioned, if you can remove the solids before they break down, you will reduce the amount of nitrate. There are 2 sources of ammonia in the tank. The first is in liquid form, and is from fish urine. The nitrifying bacteria handle this immediately. The second form comes from decaying solids, such as fish poop, dead plant matter, and uneaten food. This source is first consumed by bacteria, who in turn create ammonia as part of their life process. Again, the nitrifying bacteria deal with this. If you can remove the solids before they break down, they are no longer part of the equation, as you are removing the source.
Keep in mind that anything in the filter is still in the aquarium, visible or not. This is a common mistake, as you will often hear on here and other forums that people "only clean their cannisters every 3 months, or 6months." This is not good practice, and if you maintain your filters on a regular frequent basis, long before they become clogged, you will reduce the amount of nitrate produced. The easiest way is probably to add filter floss that can easily be removed and tossed.
As far as plants go, some are aptly called "nitrate sponges", although it is in fact a misnomer. Most aquatic plants prefer amonium to nitrate, but the end result is the same. If you remove the ammonia at the start, there will be no resultant nitrate. Plants that are good at removing nutrients are typically fast growers such as the afore mentioned anacharis and hornwort. You can actually watch hornwort grow (over a day).
Regardless, nitrate is a toxin, albeit a low level one. High nitrates while tolerable in themselves are an indicator that there are numerous waste products in the tank, that probably should be removed. Most fish in their native habitats are not exposed to any nitrate levels, and we expect them to be well in relatively high levels. bottom line is that fishkeeping is really about keeping water. Clean water is the most important factor in keeping healthy fish and having good growth rates; even more important than the quality of the food.
There are a lot of old practices in the hobby, some of which have been disproven, but carry on, partly because they get repeated as fact, when they were in fact an opinion.

 

[Yellow Eye Tang]

Once again it is very important to know the difference between NitrAtes and NitRITEs. NitrItes = BAD NitrAtes = Not a big problem. Darkmule mentioned it in the 2nd post. Good luck!

 

[richiestang_78]

For my water changes I persoanlly do 50% weekly, but do it in 25% twice a week. I generally only do one side of the tank a week that way It gets good and clean. I also clean my filter every couple weeks or so.