Seeded Fishless Cycle

[alan3513]

I'm doing a fishless cycle on two new tank, both Tropiquarium 68's (72 litre). I have put a fluval 2 plus in one and a fluval u3 in to the other that i had running in my other two tanks (In tandem with the other tanks filters). one for a few months and one for about five weeks.
I was adding 3.5 mls of ammonia each day, I didn't check any readings for the first week but started checking them at the start of the second week - Amm (dark green and off the scale in both tanks), Nitrite (1.0 in both tanks). As it was so dark i reduced it to 3mls ammonia, checking it daily and at the end of the second week -Amm still (6.0 ish in both tanks), nitrite (1.0/0.50).
Yesterday the 15th day i didn't put any ammonia in as it was still high. Checked today - Amm is still 6.0 in both tanks and Nitrite is now 0 in both tanks. Should i give it another day without Ammonia or should i start putting it back in at perhaps a lower dose ?,
Sorry if it's a bit long winded, thanks in advance for any advice, Alan

 

[alchemist]

Unfortunately you were over dosing your ammonia - I would wait until the ammonia gets down to 3 ppm - then calculate how much you need to add to get back up to 5ppm. Then follow the add and wait method - wait until its dropping then top up to 5ppm and wait again.

It is strange that your ammonia is 6 and nitrite is 0 --- the only way I can account for that is because the ammonia was so high - you may have formed a different type of bacteria colony that handles the high ammonia concentration and not the lower.

I expect you will have to basically go through a full cycle again - keep an eye on the water stats - and I expect you will see nitrite rise and fall again. Then you can check nitrate as well - and you should see this rising.

 

[alan3513]

Thanks for the reply, i was adding the amount it said on the forums calculator for my tank size so don't understand why the ammonia would be so high. Surely the fact that both filters were seeding for weeks/months in my other established tanks should have made a difference and been able to process the ammonia quicker, ?, thanks, Alan

 

[alchemist]

Assuming a 9.5% concentrate from the bottle - you needed to add 3.7 ml to your 72 litres to get 5ppm.

Next day your ammonia would still be 5ppm - so you needed to add 0ml. you added another 3.5ml - so then your ammonia was 10ppm (much to high) - each day you were adding more and more ammonia and it wasn't going anywhere - or a little was getting processed (assuming no water changes)

So what you need to aim at now is waiting for your ammonia to drop to 3ppm - then add 1.5ml - to get you back up to 5ppm. As time goes on - you will see that it gets faster and faster dropping from 5ppm down to 0ppm - you need to add the appropriate amount of ammonia to get back to 5ppm. To start, you may wait a week before you need to add anything - as time goes on you may be adding 1.5 ml a day - then 2ml a day - and eventually you will be at your target where you will be adding 3.5 in the morning - and 3.5 in the evening - and 5 ppm is getting processed down to 0 in 12 hours - but this could be several weeks down the line.

As you had mature media - and a cycle of some-sort did occur - your process may well be accelerated.

 

[alan3513]

thanks again