Our first tank

75% water change done

Is it worth doing another test for Nitrite and Ammonia tonight or just leave it a while until after I've put some SafeStart in tomorrow?

I've ordered 2x of the 50ml bottles of SafeStart as strangely it works out cheaper than buying the bigger bottles on Amazon right now.
It was mentioned to use double the amount it says which I believe will be pretty much the whole of the two bottles for my tank?

Daily tests and if necessary water changes until you get the safe start.

Thought I’d update

I added the double dosage of the SafeStart as instructed, and today is 9 days since doing it so thought I’d do a test.

It seems to have done the trick nicely.


So thanks for the help there

What’s my next steps?
1) Should the Ammonia and Nitrite all stay like this unless I do something like overfeed or overstock the tank?

2) Do I need to add any more SafeStart or other things providing nothing bad happens with the levels or fish?

3) When do I next do a water change and how much?

And finally

4) When is it recommended that I do anything with the filtration (like clean it or replace any of the bits)?

Thanks again for all the help so far it’s appreciated.

fishy_sean94 said:

Thought I’d update

I added the double dosage of the SafeStart as instructed, and today is 9 days since doing it so thought I’d do a test.

It seems to have done the trick nicely.
View attachment 101448

So thanks for the help there

What’s my next steps?
1) Should the Ammonia and Nitrite all stay like this unless I do something like overfeed or overstock the tank?

2) Do I need to add any more SafeStart or other things providing nothing bad happens with the levels or fish?

3) When do I next do a water change and how much?

And finally

4) When is it recommended that I do anything with the filtration (like clean it or replace any of the bits)?

Thanks again for all the help so far it’s appreciated.

Click to expand...

Glad to hear things have improved.

1) Ammonia and Nitrite should always stay at 0 in your tank. If you see any amounts of them a water change is required. You may see the Nitrate increase a little at times due to food and waste but this is mostly easily resolved with water changes.

2) No need to add anything more. Safe start has done its job it seems so just wait until 14 days are over and keep measuring results to ensure they're consistent and you're not getting ammonia nitrite or nitrates above 40. Always try to limit the use of any chemicals etc they're not nice for the fish.

3) do your next water change on the 15th day after you added the SafeStart of 50%. This should become your regular practice to change 50% water weekly thereafter.

4) There is no need to clean the filter or replace it just yet you haven't even finished cycling yet. It depends on which filter you use and how dirty it gets. Generally cleaning the filter once a month would be reasonable or for some powerful high quality ones you can go longer without cleaning. Just remember that when you do clean the filter it needs to be cleaned in the tank water you removed and not under tap water or you will destroy your nitrogen cycle possibly!

Let us know what filter and filter media you have so we can help further.

Styla12 posted as I was typing


1) Now that both ammonia and nitrite are zero, they should stay like that. Test every day for a few more days just to make sure.

2) You don't need to add more Safe Start unless you add more fish; although it may not be necessary, if you have some left, use it then. More fish means more ammonia being made in the tank so both ammonia and nitrite eating bacteria will have to catch up. Adding a few more may well speed the catching up process.

3) Assuming the levels remain at zero during the next few days, you need to change at least 50% once a week. This is to remove nitrate and the countless other things we can't test for which build up in the water.

4) Wait a couple of weeks, then clean the filter every couple of weeks. Wash the media in old tank water that you take out during a water change. Squeeze sponges, swoosh ceramic media in the water. The filter casing can be washed under the tap. If the flow of water looks to be falling, check there is no debris clogging the impeller.

Thank you both of you for the continued help
The filter system is just the standard one that comes included with the Fluval Flex tank which I believe just has the outer sponge, a bag of carbon and a bag of ceramic media.

I also added a piece of drift wood to the tank (in the back left compartment so it can't be seen) on the basis I was told it would naturally lower our PH a little, but it doesn't seem to have worked as it's still 8.2 which it always has been.


Not the best picture (the water is actually crystal clear and it seems difficult to get a decent one due to lighting/fast fish movement) but heres an updated one with some new moss balls I've added.

It’s looking good!

Man I love the FLUVAL FLEX, I just can’t afford one, lol.

If you have hard water, as the pH suggests, wood will have little impact. Where GH is high, KH is also usually high and KH buffers the pH to stop it changing. Where KH is low, wood can lower pH.


Re the filter media, the instructions say to replace the sponge every 12 months and the biomax every 2 to 3 months. Ignore this, they just want your money. The sponge needs to be replaced when it goes into holes or won't go back into shape after squeezing; biomax needs to be replaced when it starts to crumble. Just wash them in old tank water.
The carbon insert will get full and stop adsorbing things. You can replace that every few weeks as they suggest, or leave it there and just wash it, or the best option is to replace it with more sponge. Carbon is not needed on a routine basis, just to remove medication when treatment has finished if you ever have sick fish.