chlorine and bb

[the lion who ate the sun]

I've seen it debated a number of times, but could not garner any conclusive evidence one way or the other, so here goes:

Will a few hours exposure to chlorine kill the beneficial bacteria in my sump? I just performed a 75% water change on my 300g (135g k1 bioreactor sump) and realized I only have enough prime to treat 50% of my total water volume. I cannot fetch dechlorinator for several hours. Should I leave my pumps off for now?

Also, does it matter when prime is added when treating a full system? I typically drain-> replace 50% of water volume-> add 50% of the prime dose -> replace remaining water-> add the rest of the prime-> bring sump to capacity-> add final cap directly to ssump for good measure. Can I just put it all in at the midpoint?

My water does not have chloramine.

 

[Yuki Rihwa]

Do you know how much chlorine content in your tap water?
There is change that 50% dose of prime already over dose your entire system.

 

[Lepisosteus]

Do you know how much chlorine content in your tap water?
There is change that 50% dose of prime already over dose your entire system.

This is very true

 

[the lion who ate the sun]

No idea. I had never thought to test it. The amount of prime I use has been consistent for years, so my fish should be used to any overdosing, I would think.

The tank has been without filtration for two hours now, but I'm about to be able to add more conditioner. Now I'm not sure how much to add. To make matters worse, wal mart is the only option at this hour. They don't sell prime. Only api stuff. *head spins*

Any chlorine test kits you would recommend?

 

[Yuki Rihwa]

100% sure nothing goes wrong with your 50% dose of prime, turning off your filtration for too long do effect your water parameter though I never treat full dose of prime in all my tanks for years and nothing wrong with it, only use 50% or just dose enough of prime for the replacement water that I took out.
*Check out your local water report, usually they will tell you all chemical content in your water.

 

[the lion who ate the sun]

Thanks. I added a 50% dose of jungle labs start right to be sure.

Is that information on my water bill? I usually look immediately at the cost and toss it. Can't seem to find one around the house.

Would it be located online, perhaps?

 

[Drstrangelove]

Will a few hours exposure to chlorine kill the beneficial bacteria in my sump?

It's not the length of time----but the amount of chlorine/chloramine AND the length of time together. Long exposure at low levels and short exposure at high levels can kill off the BB if the amounts are sufficient. The actual amount of BB that die will therefore be unpredictable unless you know both the amount and the time before they are exposed.

Also, does it matter when prime is added when treating a full system?

It might (see above.). If you have a high chlorine level, and you expose the BB to that water a "while" before it's treated, it may do a little or a lot of damage. The best practice imo is to dose before you add the replacement water.

 

[Drstrangelove]

Thanks. I added a 50% dose of jungle labs start right to be sure.

Is that information on my water bill? I usually look immediately at the cost and toss it. Can't seem to find one around the house.

Would it be located online, perhaps?

This will not be in your bill unless you have a 1 in a thousand water supplier. Instead, look for the annual water treatment report which nowadays is normally online.

However---keep this in mind.

1) the measurements they provide are not the ones at your house. Readings may be higher or lower at your house, depending on factors that included distance from the supplier.

2) plants change chlorine levels from time to time during the year for various reasons. Low levels one month might become high levels next month. The plant will err on the side of too much chlorine, not too little.

 

[RD.]

From a past comment that I posted on this subject ..............


Both chlorine &/or chloramine can cause long term damage & even death to fish, in some cases even at low levels, especially young fish which are typically the most sensitive to these substances. Free chlorine can cause acute necrosis of gill tissue in fish, the younger the fish the worse it can be. Chlorine also has the potential to wipe out most/all of the bio bacteria in your system. In short chlorine is an oxidizer, that can burn a fishes gills & kill cell tissue, sometimes even at low levels.

The amount of chlorine and or chloramine can vary greatly from one municipality to another, as well as from one tap to another, and can also vary greatly throughout the season. There is no way that anyone on a public forum can possibly attempt to tell you what a "safe" amount is in your case unless they have the specs on your local tap water at your user end. Water temp, pH values, etc can also determine how 'safe' certain levels of known toxic substances can be on fish.

According to Edward Noga, a professor at NC State that is considered an expert in the disease & health of fish, chlorine levels as low as 0.10 mg/l (which is common in many tap water levels) can be accutely fatal in aquaria that has low levels of organics. (as in a new set up) Others have found residual chlorine levels as low as 0.05 mg/l to be toxic to certain species of fish.

There has been a TON of work done in this area over the past few decades, by a number of researchers, such as Tompkins & Tsai (1976) for anyone that is interested in understanding just how toxic both chlorine & chloramine can be in a closed system that contains fish.

The fact that your fish haven't died is positive, but that in no way means that the exposure hasn't caused damage to your fish. Again, this will be dependant on numerous factors, and can vary greatly from one hobbyists situation to another. What may be safe for some people, could prove to be a disaster for the next person a few cities or towns over.



Unfortunately the LC50 (survival time) of most tropical species of fish placed under various levels of chlorine/chloramine has yet to be established, but the bottom line is both substances are highly toxic to most aquatic organisms.

From the EPA ....

http://www.epa.gov/chemfact/s_chlori.txt

V. ENVIRONMENTAL EFFECTS

A. Toxicity to Aquatic Organisms

Chlorine has high acute toxicity to aquatic organisms; many toxicity
values are less than or equal to 1 mg/L. Twenty-four-hour LC50
values range from 0.076 to 0.16 mg/L for Daphnia magna (water flea)
and from 0.005 to 0.1 mg/L for Daphnia pulex (cladocern)
(AQUIRE 1994); 48-hour LC50 values range from 5.3 to 12.8 mg/L for
Nitocra spinipes (snail); and 96-hour LC50 values range from 0.13
to 0.29 mg/L for Oncorhynchus mykiss (rainbow trout), from 0.1 to
0.18 mg/L for Salvelinus fontinalis (brook trout), and from
0.71-0.82 mg/L for Lepomis cyanellus (green sunfish) (AQUIRE 1994).
Papillomas of the oral cavity in fish have been associated
with exposure to chlorinated water supplies (NTP 1992).

Low level chlorination (0.05 to 0.15 mg/L) results in significant
shifts in the species composition of marine phytoplankton
communities (HSDB 1994).

 

[the lion who ate the sun]

Thanks for the info guys.