How long does dechlorinator need to sit in water before going in tank

[Michael Ohair]

So my tank is killing guppies again. And it seems to be after 25%+ water changes. I use a water dechlorinator and make sure the water is the right temp before introducing it. But like clock work a few days after a water change the ammonia starts going up and the fish get sick. I'm thinking that the decholorintor isn't working and it must be killing the good bacteria in the filter and uncycling the tank. Any suggestions. Only other thing I can think is the water from the sink is really hard and the water in the tank has been filtered so there is a spike in hard water, but that shouldn't affect the good bacteria, right?

 

[kamanut]

What are your water parameters before and after a water change (ammonia, nitrite, nitrate)? What is the GH and KH and pH as well just to give us an idea. What brand of dechlorinator and is it expired? Size of tank and how many fish? What type of filter and how long has the tank been running? Thanks!

 

[Michael Ohair]

The tank is cycled, so ammonia and nitrite are both 0 and nitrate is usually around 5. The GH and KH are both off the chart and the PH is about 8

 

[Michael Ohair]

Then after the water change not much until a few days after, where the ammonia starts to go up. I caught it at .5 ammonia this time. Last time I was a little too late and the ammonia was 0 but the nitrite was 2.

 

[Essjay]

the water from the sink is really hard and the water in the tank has been filtered so there is a spike in hard water

Can you explain what you mean by this? Do you mean the tank water has been filtered through the tank's filter or are you using some other type of filter to change the hardness?
The tank's filter will not affect the hardness; the tank's hardness should be the same as the tap water hardness unless you do something to change the hardness in the tank.

 

[Michael Ohair]

Can you explain what you mean by this? Do you mean the tank water has been filtered through the tank's filter or are you using some other type of filter to change the hardness?
The tank's filter will not affect the hardness; the tank's hardness should be the same as the tap water hardness unless you do something to change the hardness in the tank.

Ok that is good to know. I just assumed the filter cartriges where like the filters in a britta or something.

 

[Essjay]

No they are completely different.

If you mean carbon cartridges, they do not affect hardness. All carbon does is adsorb organic matter (including fish medication). Brita filters do have carbon in them but they also contain a different type of resin which is the stuff that reduces hardness. If you open a Brita cartridge you'll see black bits (carbon) and white bits (the ion exchange resin)

 

[seangee]

It should work almost instantly. The main reason we use it is because chlorine burns the fish gills. At 25% water change it is unlikely to kill off all the bacteria even if the product was not working. How often do you do water changes?

 

[Byron]

I agree on the water conditioner...unless you overdose it excessively but it is more likely to harm fish than bacteria. There is likely something behind the scenes here and we need to find it.

As seangee asked, can you detail your water changes, frequency and volume of tank water changed? And filter rinses...how often? Are any other additives going in the tank beside the conditioner? A photo of the tank might tell us something, it will show the fish species and numbers, plants if any, etc.

What is the substrate composed of? Some will leech ammonia.

 

[Michael Ohair]

Its a 10 gal tank with 5 guppies. Only the water conditioner is used in the last few months. I don't rinse the filter but I do put a new one in every 2 months. I do water changes about 2-3 gallons every week. The water is crystal clear. The rocks are the cheap pink rocks that you get from Petco.

 

[seangee]

Do you lose fish or have nitrite spikes every week when you change the water, or is it every two months when you replace the filter? Those replaceable cartridges are great for business but terrible for fish. Every 2 months you are throwing out a whole lot of beneficial bacteria and replacing it with a sterile uncycled cartridge. If you happen to do a gravel vac at the same time you are disturbing the waste in the gravel so whatever does not get sucked up goes into the water column. So the time your water contains the most waste is also the time the filter is least able to deal with it, and your tank goes into a mini cycle.

Ok that's just a theory but seems the most likely culprit. So what could you do about it?

• Increase your water changes to 50-75% every week (crystal clear water is not an indicator of water quality)
• Replace the cartrige with a piece of sponge cut to the same size and shape. Rinse this out in the tank water you remove every week, don't replace it until it falls apart. If there is space in your filter add the sponge a few weeks before you remove the cartridge to avoid the same thing happening next time. In the meantime rinse your cartridge in the same way every week.
• Vacuum your gravel every week - this is less important if you have a sand substrate.
• Plant some plants. Fast growing plants are best. Floating plants are also really good for this. If you can get these growing before you remove the filter cartridge it will help a lot.

 

[Brian Bowers]

I had The same problem with my guppies, I just stoped keeping them. I don't know how to answer your problem. Is it just the Guppies that are dying or is it other fish?

 

[Colin_T]

if you get ammonia and nitrite readings then your filter is not established and your tank is cycling. do a 75% water change every day and let the filter settle down.