Water Changes Bad?!?

Discussion in 'Water Changes' started by BBKilbourne, Apr 25, 2017.


Frequent Correctly Done Water Changes

  1. Good?

  2. Bad?

    0 vote(s)
  1. BBKilbourne

    BBKilbourneNew MemberMember

    Ok so recently I started volunteering at my son's elementary school cleaning the fish tank... when I arrived the water was so green and dark you couldn't tell that there were any fish in it (see photo) - anyways I have worked for almost two months now to slowly clean and get the tank clear (see photo) - so I'm at petco getting some friends for the two black skirt tetras in the tank... because one they are schooling fish, and two the tank was looking sad with just the two black skirt tetras and the other two fish which I am now thinking are another kind of tetras - back on topic I tell this whole story to the woman at petco... she precedes to tell me that I should never have done any water changes (what?!?) and that she doesn't really feel good selling me any more tetras... I enventually got her to sell me 4 more black skirt tetras BUT I AM SO CONFUSED! According to her I shouldn't be doing water changes - I'm sorry but my dad had fish tanks while I was growing up and I've have several in all different sizes and I was under the impression correctly done frequent water changes were what I was suppose to be doing??!?!

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  2. Demeter

    DemeterFishlore VIPMember

    Yeah, I highly doubt that woman knew what she was talking about. Water changes are the single best thing you can do for your fish (other than feeding them correctly).

    The only thing I can think that would make the employee believe water changes are bad is that she thought it would mess with the nitrogen cycle. So long as you didn't completely change the filter media and/or rinse it out in hot/cold water the nitrogen cycle should be fine.

    Good job on getting that water clear again, can't believe people let it get that bad in the first place.
  3. Mom2some

    Mom2someWell Known MemberMember

    Wow that water! What is the point of having a tank like that? What could kids learn. You are right, the petco employee is mis-informed.
  4. KeeperOfASilentWorld

    KeeperOfASilentWorldWell Known MemberMember

    Dear @BBKilbourne ,

    Depending on your stocking; you should be doing approximately %30 water changes every week.

    The green water algae problem: I would advise a full tank dose of Tetra SafeStart immediately especially with the new tetras going in. The green water is usually caused by high ammonia levels combined with too much light. High ammonia levels are toxic for the fish and for the environment. The Tetra Safe Start will cycle your tank, lower the ammonia and nitrite levels and establish a healthy nitrogen cycle for the fish.

    Please fell free to ask if you have any further questions, we will be happy to help you through the process.

    Happy Fish Keeping :)
  5. Nanologist

    NanologistWell Known MemberMember

    Did you show her these pics!? No one in there right mind would recommend not changing that water!

    There is very little BB (beneficial bacteria) living in the water column as most of it grows on surfaces, like the filter media, gravel, decor, etc. Sadly, uninformed employees like her are all too common at the big box stores like Petco. I'm just surprised she was thinking of not selling you the fish since normally their practice is to push too many fish on a customer to make a sale!

    It's completely safe and good to change the water out as long as it's properly treated and brought close to the temperature of the tank before adding it.
  6. OnTheFly

    OnTheFlyWell Known MemberMember

    Guidance has changed much over the past 40 years. I think it is hard to argue water changes are beneficial. I had good luck for decades doing small WCs even before test equipment was common. It's debatable if huge and frequent water changes are best. I reserve those for an emergency when testing water numbers are dangerous. You did what you had to do and I think it was a good decision. But you won't see me doing a 50% WC just because it is Friday.
  7. Nanologist

    NanologistWell Known MemberMember

    Do you have an accurate water testing kit?

    It would be wise to find out what the tank's ammonia, nitrite, nitrate and PH is to start. If the tank already has a complete nitrogen cycle then you'll want to see how long it takes for the nitrates to build up to toxic levels. This will give you an idea of how frequent and how much water should be changed.
  8. wapooshe

    wapoosheValued MemberMember

    Don't trust people at petco when they can't even take care of the fish they're selling.
  9. Punkin

    PunkinWell Known MemberMember

    Wow that is pretty crazy. I had a similar thing happen to me. I had some cories that were getting fin rot, and the girl at the pet store chain (the fish expert there, no less) tried to tell me I am doing too many water changes! (40% once a week). Needless to say, I ignored her.

    Also, very kind of you to volunteer to maintain the tank.
    Edit: It looks like there are some black neon tetras in there, too.
    Last edited: Apr 25, 2017
  10. Tiny_Tanganyikans

    Tiny_TanganyikansWell Known MemberMember

    Yea she's crazy. They know very little half (85%) the time. Luckily my petco has an older gentleman working there who used to have his own shop and he actually special orders stuff for me nearly every week. He actually got me some rare cichlids that they certainly never sell in store. If it wasn't for him I'd never step foot in the place if there's no dollar per gallon sale.

    Originally they wouldn't sell me more than 8 fish at a time and flat out called me a liar when I showed them pictures of my fishroom being larger than their whole small animal section.

    Nearly any information I've heard them give people is insane. "Oh you have a 2.5 gallon betta tank with algae problemsget a chinese algae eater!!"

    With that being said. I don't do large changes especially with my sensitive shell dwellers that need a consistently stable environment. Instead I do small changes frequently. Depending on the fish anywhere from 35-10% 2-3 times a week. I save large 50/60% changes for when I slack off for a couple days and nitrates are higher than 5 ppm
  11. TexasDomer

    TexasDomerFishlore LegendMember

    Actually, in some cases, large water changes can be bad. In a tank like this, if the nitrates were very high, large water changes may shock and kill the fish - fish in high nitrate tanks need to be slowly acclimated to the lower nitrate through frequent, small changes. Once you get them back down, you can go back to large, weekly water changes.

    I doubt that's what she was referring to though. I hope she doesn't keep any fish!
  12. OnTheFly

    OnTheFlyWell Known MemberMember

    Agree with the theme of this thread. Frequent and smaller WCs are better. Fish don't like drastic changes in their environment.
  13. TexasDomer

    TexasDomerFishlore LegendMember

    I don't agree with this. I do large water changes on my tank weekly. The new water should be very close to or exactly the same as the tank water, so you're not drastically changing their environment. Large water changes are fine if done properly and appropriately.
  14. Fashooga

    FashoogaFishlore VIPMember

    During my "rookie" year I made the mistake of changing too much water which resulted in some deaths. The tank was pretty dirty, In hind site perhaps changing little at a time first so they can acclimate to new water should have been the first thing to do.
  15. clk89

    clk89Fishlore VIPMember

    I know from some fish keeping books I read at the library as a kid more then a decade ago that many once believe doing water changes was bad and would kill the fish. Some have said on this forum fish stores use to sell "old water" so one wouldn't be using fresh, clean water to do water changes with. It probably had to do with the fact that people had different PH in their tap then their tank water and that killed the fish or like texasdomer said they waited too long to do a water change (having lots of nitrates) then did a large one shocking and killing the fish.

    I personally do large water changes once a week on my tanks and they are fine; however, my tap water is the same PH as my tank water and has zero of everything else. Some people do have differing PH's or have ammonia, nitrate in their tap water, fortunately there are ways to help with that too.
  16. OP

    BBKilbourneNew MemberMember

    The first week I did a 50% change... and crossed my fingers I was so nervous. Since then I have been doing a 25% a week and yes I have been using the Safe Start EVERY time I do any water changes.... three weeks in I got super frustrated, took out all the water and decor, and then scooped out ALL the gravel, which also made me super nervous but the gravel OMG green sludge coming off of it! Anyways no I like to slit open my filter cartridges and gentle add in rinsed off carbon when ammonia levels are high- I did upgrade their filter and simply put the old filter cartridge in the new filter. And yes I was thinking those were black neon tetras too!
  17. NavigatorBlack

    NavigatorBlackFishlore VIPMember

    That's an odd approach. You will see me doing water changes because it's friday. You won't see me wasting money on a test kit. They offer a very simplistic, narrow view of water. Maybe your cycle readings are fine, but minerals for your plants and fry? Hormones from fish communication building up? If you think the test kits tell you more than one tiny aspect of how a tank's water works, you are off in an unproductive direction.

    I'd change 50% daily if I could. Some of the best tanks I have ever seen did that through automated systems. Simply stand in an average tropical (or temperate stream) for 5 minutes. You may notice a water turnover...

    I've kept fish through the "old water myths" years of the 1970s to the water changing 2000s, and the improvement in fish longevity, breeding and growth with regular, methodical water changes has been the most striking development in my 50 years of fishkeeping.

    Your Petco employee has probably not worked there long, and has certainly not trained him or herself. It is a good fish selling approach - dead fish do need replacement.
  18. Zahc

    ZahcWell Known MemberMember

    Agreed Completely!

    Seriously someone needs to make a sticky or something about water changes. So many people are misinformed and believe that large water changes are dangerous and cause shock to your fish, or, they will ruin your cycle. It's crazy! Obviously there is risk if you don't do WC's correctly, but if you do them right, they are the best thing you can do for your tank imo. It's almost aggravating the amount of people see on here that won't do more than 20-25% per week because they are paranoid about shocking there fish.

    I'm with @NavigatorBlack aswell, you couldn't possibly over do water changes. 50%+ water changes a day would be the dream. Having fish in an automated/constant water change setup would definitely be the most ideal aquarium setup possible.
  19. wapooshe

    wapoosheValued MemberMember

    make that post and asked for it to be pinned :) it'll be useful to alot of people!
  20. OP

    BBKilbourneNew MemberMember

    This fish tank is what the principal uses as an incentive to improve behavior- so if you get sent to the principal but change your behavior you get to feed the fish. The principal says it actually works better than you would think as an incentive program. So yeah when she said she wasn't going to sell me any fish I almost freaked- I couldn't show back up at the school empty handed you know

    If I could get up to the school more frequently I'd probably try to do 25% changes twice a week but I can only go when the husband isn't working and can watch the one year old- so I do good to get there once a week. I'd really like to get them a much bigger tank to make it more fun to look at but I can't see the husband agreeing to let me buy them a new one haha so they are stuck with this one (I keep forgetting to take a measuring tape is but I think it's as big as my 29 gallon at home but it could just be 20 gallons, I put a filter for 30 gallons on it just to be safe though)