# Questions about freshwater aquariums and tropical fish. **URL:** \ **Category:** In My Humble Opinion\ **Created:** [May 13, 2015, 11:16pm UTC](https://boards.straightdope.com/t/questions-about-freshwater-aquariums-and-tropical-fish/719980 "2015-05-13T23:16:54Z")\ **Posts on this page:** 10\ **Page:** 2
**Author:** ![Phedre\_no\_Delaunay](https://avatars.discourse-cdn.com/v4/letter/p/839c29/32.png) [@Phedre\_no\_Delaunay](https://boards.straightdope.com/u/Phedre_no_Delaunay)\ **Post date:** [May 16, 2015, 8:17pm UTC](https://boards.straightdope.com/t/questions-about-freshwater-aquariums-and-tropical-fish/719980/21 "2015-05-16T20:17:27Z")
> [@Why\_Child](#): > > I’ve had an aquarium for most of the last 20 years now, and never found a need to put chemicals in them, (well, other than a couple times when I bought fish with Ich, and one time I had to put aquarium salt in the tank to cure something that caused a cottony-looking growth around the mouths of the fish.) My SO, however, seems to be a big fan of chemicals. ☹ “They’re necessary!” No, not so much. This isn’t true anymore. Most water systems in the US have switched from treating the water with Chlorine to chloramine, which does **not** dissipate with time like chlorine. [http://www.skepticalaquarist.com/chlorine-chloramine](http://www.skepticalaquarist.com/chlorine-chloramine) “Chloramines. Chloramines offer a more aggressive treatment for maintaining some residual chlorine in tapwater. Unlike chlorine, chloramine won’t dissipate. In fact that’s why water companies use it: chloramine remains more stable in the water mains than chlorine.” ---
**Author:** ![Phedre\_no\_Delaunay](https://avatars.discourse-cdn.com/v4/letter/p/839c29/32.png) [@Phedre\_no\_Delaunay](https://boards.straightdope.com/u/Phedre_no_Delaunay)\ **Post date:** [May 16, 2015, 8:24pm UTC](https://boards.straightdope.com/t/questions-about-freshwater-aquariums-and-tropical-fish/719980/22 "2015-05-16T20:24:23Z")
I feel that bleach is the best bet. It’s easy to remove since you’ll need a dechlorinator anyway (I like Amquel Plus, but there are many.) and unlike with ammonia you do not have to worry about any other chemicals in it. Good info here: [Using Bleach to Clean Your Aquarium](http://freshaquarium.about.com/od/maintenance/a/bleach.htm) [How to Clean Algae off Decorative Aquarium Rocks | Pets - The Nest](http://pets.thenest.com/clean-algae-off-decorative-aquarium-rocks-12208.html) ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 16, 2015, 9:25pm UTC](https://boards.straightdope.com/t/questions-about-freshwater-aquariums-and-tropical-fish/719980/23 "2015-05-16T21:25:02Z")
Table salt is good for removing stuff that needs to be scrapped. For that matter, safety razor blades are always useful. ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [May 16, 2015, 9:42pm UTC](https://boards.straightdope.com/t/questions-about-freshwater-aquariums-and-tropical-fish/719980/24 "2015-05-16T21:42:09Z")
I am very cautious about the use of dechlorinator to counteract cleaning and disinfecting doses of chlorine. Household bleach is extremely difficult to rinse off. I nearly always have to run the bleach load twice through the clothes washer because it still reeks of bleach even after two high-speed rinses. The level of chlorine that our aquarium de-chlor products are created to counteract are really incredibly low. The same as what’s in our drinking water. For drinking water the annual average has to be > [@](#): > > below [4mg/litre](http://water.epa.gov/drink/contaminants/basicinformation/disinfectants.cfm) or 4ppm. Used for household disinfection the levels are orders of magnitude higher: From the CDC website: > [@](#): > > Because household bleach contains 5.25%–6.15% sodium hypochlorite, or 52,500–61,500 ppm available chlorine, . . . a 1:10 dilution of household bleach provides about 5250–6150 ppm. So you’d need 100 to 1,000 times the dose in order to truly counteract the level of chlorine left over from disinfecting. And it’s really impossible to know how much is in there. Also, the “chlorine” in our drinking water is CL2, or Monochloramine, which is broken down to ammonia and CL2 by the water conditioner, which contains further chemicals to detoxify those resulting elements. The chlorine in household bleach is sodium hypochlorite. I’m not sure water conditioners can even address that bond? Any chemists out there? ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [May 16, 2015, 9:46pm UTC](https://boards.straightdope.com/t/questions-about-freshwater-aquariums-and-tropical-fish/719980/25 "2015-05-16T21:46:31Z")
I am interested in a Chemist’s reply, for it is recommended to use dechlorinator on purigen after it has been regenerated with bleach. Another question for a Chemist, how does chlorine leave tap water when it is left out for 24 hours? ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [May 16, 2015, 10:14pm UTC](https://boards.straightdope.com/t/questions-about-freshwater-aquariums-and-tropical-fish/719980/26 "2015-05-16T22:14:50Z")
> [@carnivorousplant](#): > > I am interested in a Chemist’s reply, for it is recommended to use dechlorinator on purigen after it has been regenerated with bleach. > Another question for a Chemist, how does chlorine leave tap water when it is left out for 24 hours? Fascinating. I’ve never heard of this stuff before. It does say use 4 tablespoons of Prime per _CUP_ of water, as compared to the usual Prime instructions of 5 ml per 50 gallons of tap water. It also says to then soak it in a buffer. > [@](#): > > Regeneration: Soak in a 1:1 bleach:water solution for 24 hours in a non-metallic container in a well ventilated area and away from children. Use regular 8.25% hypochlorite household bleach (non-scented, no dyes, do not use a splash-less bleach). Rinse well, then soak for 8 hours with a solution containing 4 tablespoons of Prime®, or equivalent dechlorinator per cup of water. Rinse well. For freshwater use, soak for 4 hours with a solution containing 2 tablespoon of buffer per cup of water (Discus Buffer®, Neutral Regulator®). Original color and full activity should now be restored and Purigen® is ready for reuse. Caution: some slime coat products may permanently foul Purigen® and render regeneration difficult. Do not reuse if odor of bleach/chlorine is detectable. In case of doubt, soak beads in small quantity of water and test for residual chlorine with a chlorine test kit. ---
**Author:** ![RandMcnally](https://avatars.discourse-cdn.com/v4/letter/r/b782af/32.png) [@RandMcnally](https://boards.straightdope.com/u/RandMcnally)\ **Post date:** [May 17, 2015, 12:04am UTC](https://boards.straightdope.com/t/questions-about-freshwater-aquariums-and-tropical-fish/719980/27 "2015-05-17T00:04:50Z")
Is there any way to have a closed system successfully? ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [May 17, 2015, 12:17am UTC](https://boards.straightdope.com/t/questions-about-freshwater-aquariums-and-tropical-fish/719980/28 "2015-05-17T00:17:56Z")
> [@RandMcnally](#): > > Is there any way to have a closed system successfully? I don’t know of one, but water changes with the hose I linked to above are so easy, I’m not sure I’d want to add more chemicals just to get rid of Nitrates. Another option some people employ, that I’ve looked into, is running a fresh water tap to the tank that constantly drips water in and having an overflow that drains it back out. If you get it set just right, your tank will change the water on it’s own every few weeks. Of course, that requires it’s own maintenance and I’m not sure how water conditioning is dealt with in that scenario since there’s a constant influx of Chlorine (or whatever the city uses). ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [May 17, 2015, 3:48pm UTC](https://boards.straightdope.com/t/questions-about-freshwater-aquariums-and-tropical-fish/719980/29 "2015-05-17T15:48:17Z")
If chemicals worry you use hydrogen peroxide for disinfecting. Drugstore stuff will do for disinfecting, but may not be strong enough for good cleaning action. The drugstore variety is usually stabilized with citric acid which washes out easily if it’s a problem at all. Get food grade peroxide if you can for better cleaning action. Don’t use the stuff made for pools and hot tubs or other specific uses because you don’t know what additives it might have. I used to have a fantastic water changer I used on my salt water vertebrate tank. Warning now, I can’t actual verify it’s effectiveness in removing chlorine, and I didn’t find it being sold anymore last time I looked. It sprayed a very fine mist of water over the top of the tank that would cause chlorine to dissipate in the air. You could smell the chlorine coming off the spray. At the same time it was siphoning out water at a slow rate. It was a slow process maybe not even a gallon per hour. Changing water is not as critical in a salt water tank with good mechanical and biological filtration so I can’t say if it would be useful for a large freshwater tank. I don’t know if it would be effective in removing chloramine either. However for starting new tanks I’ve been using the same method since I got my first tank when I was in the first grade, boil the water then wait for it too cool down. Boiling should dissipate both chlorine and chloramine plus kill most anything else alive in the water. I’m not a chemist though, couldn’t really tell you how effective it is. One more note, use the gravel vacuum cleaner frequently for water changes and just cleaning. Unless you have a reverse flow undergravel filter (which I highly recommend) then dirty gravel is your enemy. ---
**Author:** ![Phedre\_no\_Delaunay](https://avatars.discourse-cdn.com/v4/letter/p/839c29/32.png) [@Phedre\_no\_Delaunay](https://boards.straightdope.com/u/Phedre_no_Delaunay)\ **Post date:** [May 17, 2015, 5:59pm UTC](https://boards.straightdope.com/t/questions-about-freshwater-aquariums-and-tropical-fish/719980/30 "2015-05-17T17:59:45Z")
> [@TruCelt](#): > > I am very cautious about the use of dechlorinator to counteract cleaning and disinfecting doses of chlorine. Household bleach is extremely difficult to rinse off. I nearly always have to run the bleach load twice through the clothes washer because it still reeks of bleach even after two high-speed rinses. > > The level of chlorine that our aquarium de-chlor products are created to counteract are really incredibly low. The same as what’s in our drinking water. For drinking water the annual average has to be > > Used for household disinfection the levels are orders of magnitude higher: > > From the CDC website: > So you’d need 100 to 1,000 times the dose in order to truly counteract the level of chlorine left over from disinfecting. And it’s really impossible to know how much is in there. > > Also, the “chlorine” in our drinking water is CL2, or Monochloramine, which is broken down to ammonia and CL2 by the water conditioner, which contains further chemicals to detoxify those resulting elements. The chlorine in household bleach is sodium hypochlorite. I’m not sure water conditioners can even address that bond? > > Any chemists out there? Please see the links I provided in my post. I’ve been an aquarist for many years and I do this _all the time_. It works. It’s safe. I have a million\* pleco babies right now in my tank attesting to the safety of this practice. It’s even advised that you dip new aquarium plants in a bleach solution to kill any snail eggs before putting them in your tank. Bleach is safe for aquarium use. (provided you know how to rinse.) Clean with bleach. Rinse. Rinse. Fill tank. Add Amquel Plus (or whatever you use.) Cycle tank. Add fish. It’s so easy. \*Hyperbole. I probably only have half a million pleco babies. [Previous page](https://boards.straightdope.com/t/questions-about-freshwater-aquariums-and-tropical-fish/719980.md?page=1)