going from salt water to fresh water

I am in the process of changing my 90 gal. salt water tank over to fresh water. Main reason is it will be cheaper to run. I have it all cleaned I spent close to 3 weeks cleaning the tank out. Everything in it I tossed out I plan on buying new stone and sand for the bottom, I am also running a 20 gal. tank below to help with the filtertration and to alos get my plants growing. My main question is what all equimpent will I need to run and should I also get a new protein skimmer. My last fresh water tank was a 10 gal gold fish tank back in high school. I have an idea on my fish I will be putting in it and I will have all live plants and my girl friend wants a pirate ship in the bottom.

 

I have a freshwater tank I don't use a protein skimmer. Here is a list of my equipment in 100 gal tank:
-Heater
-Canister filter
-Powerhead/UV
-Airstone
-T5HO
-thermometer

 

so is that 20 gallon a sump/refugium? if so you won't really need another filter. deff no skimmer.

 

HI bigdan, Welcome to fishlore
Depending on how you want to setup your tank, you could use your existing sump as a Freshwater Refugium, although this technique is not common in Freshwater setups.

There's been some recent discussions about this:
https://www.fishlore.com/aquariumfishforum/threads/freshwater-refugium.82323/


Another aspect you may to consider is the current plumbing. Having been used for SW, chances are there are all sorts of grime/algae/sea slime in the pipes, it'd be wise to consider replacing your plumbing.

Protein Skimmers don't work on FW, so you won't need one of them. (FW doesn't foam like SW)

Lighting - If you have actinics at the moment, you'll want to replace them. The actinics don't do anything for FW. Whilst on lighting, the current white you have may be too much for a Freshwater setup. Typically a Freshwater planted setup will run 6700k up to 10000k lighting. Saltwater lights typically run around 18000/20000k, which is (typically) too much.

Powerheads - up to you, but not 100% necessary for a Freshwater setup, and might create too much flow/current for some plants.

Heaters - you should be able to re-use, as long as they've been really well cleaned.

Filters - unlike a Saltwater setup, many Freshwater setups run around 10-20ppm nitrate. This means that things like phosphate reactors and the like aren't necessary. The plants will actually feed on the nitrates and phosphates.

Water - well you won't need RO water anymore Tap water is generally used in Freshwater setups. Just be sure to treat with a quality conditioner such as Seachem Prime, or Kordon Amquel+ and Nova+

Note, I have also moved this thread to the Freshwater Equipment Forum

 

I'm not sure how I'm going to run the 20 gal. tank. My filters will be down there and there will be a light set there also to help grow plants for the tank