Water Change Impact on a Cycled Tank

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I just did this and completely screwed my cycle!!

I removed 80% of the water, enough so I could drag the tank to where i wanted it, then i put enough prime in for a triple dose on my size tank (600L) then i refilled the tank, after about 2 hours my water went like milk, my ammonia test was through the roof and my cycle was destroyed!

PRIME DOES NOT WORK FAST ENOUGH TO SUPPORT LARGE WATER CHANGE!!!

If i was you i would try and get a drum and keep your existing tank water, OR dis connect your existing filter, or turn it off, app prime, refill the tank, add use a powerhead to mix the water for at least 1-2 hours!! then reconnect your filter!

I do 80% water changes all the time with Prime with no issue. Does your water have chloramine in it? Was this after a heavy rain or around a seasonal change?


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I checked the Miami Dade water quality report, it appears they use Chloramine as a disinfectant. This would mean, whatever de-chlorination product you use, needs to be made to reduce chloramine. Most can, I use straight sodium thiosulfate, which is the active ingredient in most products, only dose what is prescribed per the amount of gallons you change.
Saving water is not as important as saving wet substrate, the beneficial bacteria live as a biofilm on substrate, rocks, etc, they are not free floating in tank water, this is why biomedia is put in filters.
I do large scale water changes daily, as long as the chloramine is removed, and temp is similar, there is no problem.
 
So it was more likely that 4D3 was having a false positive. It is pretty widely known that prime works right away.


From http://www.seachem.com/support/FAQs/Prime.html

"Q:I tested my tap water after using Prime and came up with an ammonia reading. Is this because of chloramine? Could you explain how this works in removing chloramine?

A: Prime works by removing chlorine from the water and then binds with ammonia until it can be consumed by your biological filtration (chloramine minus chlorine = ammonia). The bond is not reversible and ammonia is still available for your bacteria to consume. Prime will not halt your cycling process.
I am going to assume that you were using a liquid based reagent test kit (Nessler based, silica). Any type of reducing agent or ammonia binder (dechlorinators, etc) will give you a false positive. You can avoid this by using our Multitest Ammonia kit (not affected by reducing agents) or you can wait to test, Prime dissipates from your system within 24 hours."




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So it was more likely that 4D3 was having a false positive. It is pretty widely known that prime works right away.


From http://www.seachem.com/support/FAQs/Prime.html

"Q:I tested my tap water after using Prime and came up with an ammonia reading. Is this because of chloramine? Could you explain how this works in removing chloramine?

A: Prime works by removing chlorine from the water and then binds with ammonia until it can be consumed by your biological filtration (chloramine minus chlorine = ammonia). The bond is not reversible and ammonia is still available for your bacteria to consume. Prime will not halt your cycling process.
I am going to assume that you were using a liquid based reagent test kit (Nessler based, silica). Any type of reducing agent or ammonia binder (dechlorinators, etc) will give you a false positive. You can avoid this by using our Multitest Ammonia kit (not affected by reducing agents) or you can wait to test, Prime dissipates from your system within 24 hours."




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Really,a false positive? For the last week every day my test kits have been giving me false readings for ammonia,nitrite and nitrate even though I have only added prime once?

Doubt it...

The huge water change has broken my cycle, I knew it had with it a test kit.my moving bed filter media is usually a dirty brown color, 3 hours after water change it was pristine white as if it had never been used.

I removed my water, moved my tank, added prime, added seachem neutral regulator, added my seachem American cichlids let it mix through for 20 mins then added water.3 hours after filling everything went screwed up.



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Most of your BB are in the filter and the substrate anyway. Leave the FX5 running on a bucket or a tub of water. Put your substrate in buckets and aerate them. If I were you, I will leave the substrate undisturbed in the tank. I will instead get more people to help so that the weight of the substrate will be evenly supported when the tank is moved.
 
Really,a false positive? MonsterAquariaNetwork App

Yes, really, based on the first info you gave, which was only that "after about 2 hours my water went like milk, my ammonia test was through the roof."

The "huge water change" itself is not what "broke" your cycle, that's just not how it works. Plenty of us have done this without trouble, and some do it daily. Sorry you had to go through that, but based on your added info, it sounds like you had something else in your tap water that was not detoxified with the Prime, or you did not dose correctly.

Cheers,
 
You will be fine, for the person who drained 80% and ruined his cycle I call BS. I do a 60-70% change every time with no issues. I'll tell you the trick and reasoning behind it. Its because the beneficial bacteria in your tank does NOT LIVE IN THE WATER. Therefore removing the water will not hurt it one bit. The bacteria in fact live in substrate, decorations such as drift wood, YOUR FILTERS, but NOT the water. I would definitely keep your filter undrainned as you planned but I would also put any substrate you can in a bucket of water for the time being. Reason is while the bacteria doesnt live IN the water, it needs the water to help it survive in the substrate. Swap everything over, use de-chlorinator, and you will be just fine. Of course monitor and check all perimeters just to be sage
 
yeah. full water change didn't "break" cycle.
other factors could've affected tank. stirred substrate during the switch can released bio toxins, which were previously trapped.
 
yeah. full water change didn't "break" cycle.
other factors could've affected tank. stirred substrate during the switch can released bio toxins, which were previously trapped.

This should be done during your weekly water changes to alleviate the issue. When vacuuming stir up the substrate, especially sand, to help release any oxygen trapped that would in turn turn toxic. You wont ever have this issue in the long run
 
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