Tank and Gravel Question

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Aquarium Advice Apprentice
Jan 10, 2013
Hi all

I will be moving soon and that includes my 125 gallon tank.

A bit of back note, I bought this tank used 3 years ago. All fish have been living in it for at least the last year if not longer. I use to AC120 (I think, the largest HOB aquaclear has). No issues with any filtration or parameters.

I have two questions:

1) if I want to change out the gravel to black instead of blue that I currently have - will that cause a huge issue in cycling, etc with the move? I can save the filter media, but the water I can only save about 10 gallons.

2) I bought the tank used, I am not sure how long the prior owner had it. I do not feel comfortable resealing something of this size (particularly because I live in a condo). Should I buy a new tank so I am safe for the next bit? I have attached a few photos (sorry for their quality, my phone was trying to focus on the fish and not the tank).



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One of the issues I've found with moving large tanks is that they settle in their old space so they may not be 100% square anymore and if you move them, even onto their existing stand, they may still need to shift to accommodate the new position. The way around that shift being serious is to use a thick bed of Styrofoam under the tank so that the styro absorbs the tank as it is vs the tank needing to shift. For a tank that large, I suggest the styro be at least 3/4" -1" thick. I just use the pre packaged Styro sheets at Home Depot or Lowes. ( similar to this: https://www.homedepot.com/p/3-4-in-...-Insulation-Sheathing-6-Pack-150705/202090272 )

As for changing the gravel, Yes, it will effect your bacteria bed somewhat because the bacteria bed is anywhere in the tank that has good oxygenation so the gravel can be that area. You will need to keep your filter media wet during the move but if you are not going to get the tank back up and running for more than a day, I suggest placing the filter media in a container ( i.e clean tote, clean garbage can, etc) and run an airstone in the container to keep the oxygen level up. If you use a container large enough to house some fish as well as the filter media, they will keep the bacteria bed fed with ammonia while they wait for the tank to be reset. Another option is if you transport your fish in a container similar in size to the container the filter media is in, you can transfer water from the fish container to the media container 2 times a day and replace with water from the filter media container so that the fish are getting clean water and the bacteria bed is getting fed as well to keep it healthy. ( Test both waters to make sure all is going according to plan. (y) )

On a side note, you may want to use a bacteria booster when you reset the tank up to help compensate for lost bacteria from the old gravel. There are a lot of options of boosters but I have only found Fritzyme #7 ( for freshwater) or Fritzyme #9 (for saltwater ) to actually work. :whistle: Due to the weather conditions, you may want to pick this up from a shop vs having it shipped to you as the bacteria can die in the bottle if it gets too hot or too cold. Look for an expiration date and get a bottle with the latest expiration date. (y)

Hope this helps. (y)
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