[John Tashjian]

Hello i have a 39gal tank. Just removed fish and installed an in of sifted organic topsoil, 3 bags of eco complete and a 5lb of black sand for the finer plants in the front. I used the original water but unfortunatly the filter was filty so it is cleaned. I will check ph, ammonia and nitrates. How long before i can add the fish???? Thanks in advance.

 

[Zoidburg]

If the water parameters check out fine, possibly immediately. However, moving the sand and cleaning the filter could cause it to go through a cycle again, and if it does, as soon as the cycle is over and a water change done - if required.

 

[John Tashjian]

Thank you zoidburg. I will check all water parameters first.

 

[John Tashjian]

Ammonia non existent, nitrates normal but i noticed the ph was very high at 8.4. I lowered the ph and will check it tonight. If it is close to 7 i will move the fish to there new home. I cant wait to see increased plant growth.

 

[GraphicGr8s]

Something has to be causing your pH spike. I've found that pH is one of the hardest things to control. If you have something in your substrate that is buffering it you will be fighting a losing battle. I would have waited for things to settle before I looked at ph.

I've done many dirted tanks. It's not the end all be all some think it is. I've got one left out of a couple dozen I had. Don't get me wrong. I still use dirt. And plenty of it. I just am more judicious in its placement and now have it in terra cotta pots or net pots to get plants started. I never clean the gravel. They do very well and I don't get the mess when I rearrange plants.

 

[John Tashjian]

I lowered the ph and the fish are doing well so far. This is my first dirted tank and i am hoping all plants will explode.i want to try carpeted plants also in the sand.Pics to follow.

 

[GraphicGr8s]

I lowered the ph and the fish are doing well so far. This is my first dirted tank and i am hoping all plants will explode.i want to try carpeted plants also in the sand.Pics to follow.

Sure you can lower the pH. For a while. But it's a battle you will never win. The dirt and other materials breaking down should cause more acidic environment anyway.

Every planted tank I've done has been a different experience. The last one I have setup was interesting. For years the swords and the anubias grew but real slow. Then all of a sudden last year they exploded. The anubias has 3 spathes on it now. The swords have also taken off as have the newer stems I put in.

 

[Diana]

Back to the original question:
If you redo a tank, how soon can you add back the fish, from the point of view of how established is the population of nitrogen cycle bacteria.

Let me answer the question with a question:
If the new set up has lost some or most of its bacteria....
So you want the bacteria to regrow....

Where are you going to keep the fish, anyway? Do you have another fully cycled tank they can go in, and not cause an ammonia spike because of the large increase in fish population? Can't just keep them in a bucket, or a spare tank that is not any more cycled than your new set up. (and probably has less bacteria).

And how were you going to raise more bacteria in the new set up?

Answer:
1) Refill the new set up with water that matches the original water. Same GH, KH, TDS. pH is less important. Do not add pH altering materials JUST to make the pH match.
2) Put the fish back as soon as the tank water has cleared.
3) If there is any doubt about the population of nitrifying bacteria add a source that includes Nitrospira species of bacteria. Read the label and do not waste money on anything else.