how to change to sponge filters in an established aquarium

[Kathey Hedge]

I purchased the required materials from your website to change my Marineland biofilter to your suggested system of coarse filters, bio rings and the fine poly filter.  My nitrates were high so I was doing almost daily water changes.  I also added live plants.  Now my nitrates are low (less than 20 ppm).  I have a 75 gallon tank.  after decorations and substrate, 63 gallons of water.  I have 2 gouramis, 1 pleco, 3 danois, and 15 tetras.  I have 4 sword plants, 1 java fern plant, 6 marimo moss balls, 2 dwarf sagittaria and 3 crypts.  I do not know how to change my Marineland biofliter system to your biofilter with the different sponge systems and biorings without a totally changing the positive bacteria???  I have watched all of your videos and read every blog on your website.  I know how to change my fliters but do not know if will affect my positive bacteria???  Just fyi, I had a male gourami but he passed away from unknown causes (I bought him from the glofish website and they refunded my money after i send pictures), i also had more danios but they "disappeared"  as did 4 of my tetras.  I might be considered obsessive but I check my water parameters daily, and phosphate levels every week and KH and GH every other week.  

I am also need to know if the snails in my "quarantine tank" need any food?  I think the snalis came with the plants I ordered from your website.  The plants are showing new growth except the villisneria.  I do have a "black thumb" so was hesitant to try aquatic plants.  I am trying the live plant "cycling" in my 20 gallon tank.  It is supposed to be my quarantine tank but I think of it as my death tank.  that is a longer story.  anyhow, how do I change my biofilter to your system while maintaining the positive bacteria and do the snails need food in my cycling tank?  

 

 

[Cory]

Place the pre filter sponge on the intake for 10-14 days. This will colonize bacteria. Then you can remove your cartridges and put in the media. Alternatively when it's time to change your cartridge, just swap in the new media. If you were swapping cartridges you were losing the bacteria anyway.

 

As for your quarantine tank need a food source, if you want it to handle a bioload then it'll need a source to keep the bacteria alive. In reference to the plants, make sure you're fertilizing them and have a good plant light and they'll continue to grow. Vallisneria likes both root tabs and liquid fertilizer.