Should I Do Filter Or Water Changes During Fishless Cycling?

Having just read the other thread - do you have any other tanks at the moment? If you do, you can speed up the cycle enormously be stealing some media from a mature tank. It is safe to take up to a third of the media from an established tank.



To answer your question, during a fishless cycle using ammonia solution you do not need to either clean the media or do a water change, with a couple of exceptions.

If the media becomes clogged with something, then yes, clean it. Very carefully as the bacteria will not yet have a fully established biofilm.
If the pH crashes off the bottom of the scale, you will need to do a water change to replenish KH. This only happens with very low KH, which usually goes with very soft water.
If you accidentally overdose ammonia, you will need to do a water change to get it back down to 3 ppm.

Otherwise, you won't need to do water changes or filter cleans until the cycle has finished. Before getting transferring fish from the old tank you will need to do a very large water change to remove all the nitrate you have just been making.

I see in the other thread that your new tank is a Juwel Rio. Just a heads up on Juwel media:
You don't need the black sponge as carbon is not needed full time.
The green sponge doesn't work at removing nitrate. Treat it like a blue sponge.
The white pads clog quickly as they are first in the direction of water flow to catch the debris. They don't wash well, as they go into holes quickly. Rather than buy expensive Juwel pads, get a length of filter wool/filter floss from a roll and use a white Juwel pad as a template to cut it up.

And ignore what Juwel say about replacing sponges - though you probably already know that 

Most filter manufacturers tell you to change the media every few weeks or months. This only actually applies to carbon, but then you don't need to use that full time anyway. Just keep a carbon sponge or granules in the cupboard to remove medication after treatment has finished if the fish ever get sick.

Sponges should be squeezed in water you take out during a water change until they go into holes or won't go back to shape. Ceramic media should be swooshed in old tank water till it starts to crumble.
They only want you to buy new media so it makes them more money.

Are the plants growing very well? If they are, I would suggest doing a big water change to get rid of the nitrite and buy the first batch of fish. Monitor both ammonia and nitrite to make sure they stay at zero., and do a water change if they show above zero.

Plants prefer ammonia as their food source. They will use nitrate and also nitrite to some extent, but they have to convert them back to ammonia to assimilate them. If there are plenty well growing plants, they should use most of the ammonia - and they don't turn it into nitrite. This is called a silent cycle. It does, however, mean that you have to add fish in batches, and only add the next once when you are sure that ammonia and nitrite aren't going to show up after the last addition.


The nitrate test also measures nitrite, so if nitrite is high, the nitrate test will show a higher reading than the actual level of nitrate.

Well, my fishies remain unmoved.

I've carried out a 60% water change, but my Nitrite is still reading as 3.3.

My Ammonia remains 0 and the algae is thriving 

I have, however, now taken one of the blue filters from my old tank to see if this will help.

Is there anything else I can do, or shall I just keep adding ammonia and try another water change in a few days?

Brilliant, thanks Sue, I shall report back!

That's good news 

You do realise we all expect photos once they have settled