A Note On Water Changes - Why Big Numbers Are Important

[DreamertK]

Just want to add on: I've been having a horrible nitrite problem from the cycling. Every day for the past week I've been testing it (~1-2.0 ppm) and doing a 50% change and the next day it rises back up to about the same amount (just slightly less, its horrible to tell the difference in these colors). Tap tested negative for nitrites. Today it was ~1-2.0ppm (I seriously cant tell, they're all the same shades of purple on this card), did an 80% change and now I've tested it and it's 0.15. Finally this madness might be behind me for a little while.

 

[ColR1948]

@ DreamertK, you don't happen to have a dead fish in the tank hidden somewhere by any chance, or have you done a rescape with the fish still in?

I had both these things happen to me in seperate tanks, in the rescape one I disturbed the substrate to such and extent it caused a Nitrite spike, and in another tank I had a dead fish that I hadn't missed, it was hidden behing some rocks.

 

[balajake]

I'm a big fan of big water changes. If I had 2ppm of nitrite or ammonia I would do an 80%-90% water change and supplement with prime. I do 60% a week every week anyway on my tanks

 

[snazy]

The only reason someone would be arguing of how much water to change on regular basis is to actually avoid doing large and regular water changes. All sensitive fish require large and regular water changes so why wouldn't not so sensitive fish benefit from them? Not changing the water regularly will eventually take it's toll for sure, it's just a matter of time and the period of time differs from tank to tank. It may take a year or more for the tank to crash and show sudden multiple problems, so that's why the folklore around the forums that "my tank is fine" without too much water changes because it just hasn't happened yet but it will. Also, people tend to accept for normal a fish death a lot easier than other pets. But if everything is fine and was always fine why can't people keep fish that live 5-6 years for no longer than 2 years for example?

And I've noticed over and over again how people don't take into account how much water to change when they have an ammonia/nitrIte or nitrAte problem. If you've got any ammonia and nitrIte, these has to be removed at once down to nearly 0 no matter how much water it needs to be changed. The shock of these toxins is way greater than the shock of adding water with different parameters which actually can be avoided if the water is added slowly.
I keep reading posts like, I have 2ppm ammonia and I do 50% water changes daily. So how is that any good at all? The fish will die in 1ppm ammonia as easily as in 2ppm ammonia. Maths doesn't seem to the best asset of fish keepers

Personally, with 50% water changes weekly the nitrAte levels never rise above 20ppm in my tanks, the tanks are well stocked/overstocked and I tend to overfeed. One of the tanks even needs nitrAtes added as it bottoms out because of the plants. So it doesn't need that much extra time and effort to keep the levels in check at all times and my observation is based on 3 tanks, and a 4th one a couple of months old. This of course may differ for other people but finding the balance is what needs to be done and then keep it that way.

 

[balajake]

People believe that small water changes are better than larger ones because it can upset the balance of the tank and scare the fish which is Absolute tosh. My fish absolutely adore large water changes and swim in the stream under the bucket as I'm adding the water lol. If a fish tank has been neglected then I would say be cautious and build up the amount slowly over a few months, but definately get them up to at least 40% a week with the correct declorinators etc regardless of the tank size because just because a tank looks ok doesn't mean it is ok and my fish perk up unbelievably when I've changed my water.

 

[Yanks15]

Snazy, I agree 100%. I change 50% every week and my stats stay constant. I do know people that do water changes once a month and rarely even vac the substrate and have no problems with their fish................yet! Educating people about proper care of any pet ends when the discussion ends and then it's up to them to act. If they care about the welfare of their pets, whether it be fish, cats, dogs, ferrets, etc, they will do the right thing. I treat my fish the same way I treat my dog. I give them both high quality food, fresh water when needed, and plenty of interaction. My last dog lived 13 happy years. I hope my fish will live a long life, happily, me knowing that a tank is not where they would choose to be.


Thanks,
Steve

 

[DreamertK]

@ DreamertK, you don't happen to have a dead fish in the tank hidden somewhere by any chance, or have you done a rescape with the fish still in?

I had both these things happen to me in seperate tanks, in the rescape one I disturbed the substrate to such and extent it caused a Nitrite spike, and in another tank I had a dead fish that I hadn't missed, it was hidden behing some rocks.

I only have two fish. I would certainly hope theres no extra dead fish in there. Though NH3 has been trace/zero. Just doing a fish cycle is why the NO2 /nitrite is so high. Have to keep doing the daily large changes to get the levels as low as possible.

I still think my fish hate the water changes, always hiding under the driftwood for an extra hour after I'm finished. (Water temp remains within 1 degree of 78 when adding new water) Though I suppose it's the only time when they're not fighting for top gourami position. One time I saw my other gourami hugging my mama gourami under the drift wood. If they weren't so afraid I would have thought it was adorable.

 

[PrairieSunflower]

I don't understand the math at all... but I do two weekly changes... half week of about 30-50% and weekend of 50-80% and it keeps things happy... that's all that matters to me.

 

[bmonki]

Well I understood it, but I'm a geek.

 

[Memz]

Understood but......

How come if we're not supposed to rinse the filter with tap water due to messing with the funky stuff that keeps the water happy are we allowed to dump in 80% of the stuff and expect the filter to cope?

Just asking..... I do large water changes weekly

 

[tata]

If you are doing 80% WC, is because the water conditions are so poor, that in fact you aren't risking to much.

Anyway, if you use a water dechlorinator, you won't harm Nitrifying Bacterias, so filter will keep doing his job.

 

[Memz]

Got it. I thought the dechlorinator was to protect the fish. Makes perfect sense now how come the tank doesnt go into a cycle everytime people do massive water changes. Thanks.

 

[tata]

Yeah, it's to protect both the fish and the nitrifying bacterias which are all over your aquarium, but specially on the substrate and inside external filter.

 

[raptorrex]

lol, I've never heard such a load of,........ in all my life!
People seeing things that are not there here.

Change how much you like, 25-30% is more than enough.
Unless of course, you have other problems.

None of the evidence here stands any reasonable scrutiny.

In fact most is pure ?


sure, state it as "your view".
but dont pretend its "fact", or even considdered as reasonable practice.


no wonder this forum is slipping, if this is how its going.

 

[fluttermoth]

I think you're being overly harsh there, Raptor.

Most fishkeepers would agree that larger water changes are more effective than smaller ones, and it's something newbies to the hobby often underestimate.