fluval 13.5 gal HELP!

[fishfish2468]

hi! new to this hobby and honestly a little confused. just bought the fluval 13.5 gal tank, have the fluval protein skimmer in chamber 1, the original filtration in chamber 2 and original pump and heater in chamber 3. I am not planning on any coral but plan to stock it with as much fish as I can. I've read that the original filtration is not very good. what can I switch to and how do I set that up. also have live sand and dry rock

 

[bubbgee]

Probably move the skimmer to chamber 2 and add carbon and filter pads in chamber 1. Then have a regimen to replace carbon and pads regularly depending on how heavy you feed your fish.

 

[Shnetts]

in that tank your going to comfortable be able to have 3 fish, maybe 4 if they are all tiny. You dont have to complicate the filtration as much as you think, the majority of your filtration will come from the rock and sand in your display. filterpads are there to filter out bigger particles in the water, carbon to remove any unwanted elements.

 

[fishfish2468]

should i keep the protein skimmer? how do i upgrade to all those things?

 

[ga2040]

Fluval mini skimmer can be added (first chamber away from pump)to one of the slot on the upper side lid. You will have to break that square piece of plastic om the side lid.
I have used that system many years back. Filteration is good (middle chamber) but you can upgrade the sponge .

 

[fishfish2468]

i’m having trouble getting the protein skimmer to bubble. it bubbles a little but doesn’t reach the collection cup. i’ve played with with valves a little and got them to work a little bit but not fully

 

[Mr. Mojo Rising]

If you have nothing in the tank yet, then there is nothing for the skimmer to skim.

Weekly water changes will be the main filtration on that size tank, the tank is just too small to upgrade the filtration equipment too much.

Besides filtration, space (which you don't have a lot of) and rockwork determines how much fish you can stock comfortably in that tank, but I wouldn't do more than 3 fish.... even just 2 clowns is overstocked in that tank.

 

[ga2040]

i’m having trouble getting the protein skimmer to bubble. it bubbles a little but doesn’t reach the collection cup. i’ve played with with valves a little and got them to work a little bit but not fully

Check the water level of the tank and play with it. It may need to be a bit high if i can remember.Also it can take a few hours for it to even start producing bubbles.

 

[Fish Fan]

Is this one of the Fluval tanks that comes with the giant foam block? If so, I might suggest going with a media basket, something like this one from an Etsy seller (there's others too). This way you can run more typical medial like filter floss (I use Poly-Fil), Granular Activated Carbon (GAC) or even some extra biomedia (used in case you need to quickly cycle a hospital tank):

Fluval Sea Evo 13.5 Media Baskets - Etsy

This Aquariums & Tank Decor item by PrettyPrintShopCA has 39 favorites from Etsy shoppers. Ships from Canada. Listed on Sep 1, 2025

www.etsy.com

Unfortunately, you're not going to get a whole lot of fish in this tank. Remember that the display area is closer to about a ten gallon tank. And water changes will go a long way to keeping your tank in good shape. I'd suggest getting a food-grade 5 gallon bucket from your local Mega-Lo-Mart, a small circ pump and a heater. Use this to premix and heat your saltwater, and then you can safely change out a larger percentage of the tank's water without stressing the livestock.

Last, don't be afraid to try some easy soft corals, the stock light should be enough for things like Green Star Polyps (GSP), mushrooms, leather corals, Zoathids, etc.


Good luck!

 

[fishfish2468]

Is this one of the Fluval tanks that comes with the giant foam block? If so, I might suggest going with a media basket, something like this one from an Etsy seller (there's others too). This way you can run more typical medial like filter floss (I use Poly-Fil), Granular Activated Carbon (GAC) or even some extra biomedia (used in case you need to quickly cycle a hospital tank):

Fluval Sea Evo 13.5 Media Baskets - Etsy

This Aquariums & Tank Decor item by PrettyPrintShopCA has 39 favorites from Etsy shoppers. Ships from Canada. Listed on Sep 1, 2025

www.etsy.com

Unfortunately, you're not going to get a whole lot of fish in this tank. Remember that the display area is closer to about a ten gallon tank. And water changes will go a long way to keeping your tank in good shape. I'd suggest getting a food-grade 5 gallon bucket from your local Mega-Lo-Mart, a small circ pump and a heater. Use this to premix and heat your saltwater, and then you can safely change out a larger percentage of the tank's water without stressing the livestock.

Last, don't be afraid to try some easy soft corals, the stock light should be enough for things like Green Star Polyps (GSP), mushrooms, leather corals, Zoathids, etc.


Good luck!

I was watching other peoples videos and they said they had a plug to cover holes from chamber 1 to 2. do you think ill still need that with that media basket?

 

[Fish Fan]

I was watching other peoples videos and they said they had a plug to cover holes from chamber 1 to 2. do you think ill still need that with that media basket?

I guess I'm not sure, I've never had one of those tanks. I'm sure someone here will know for sure.

 

[myminireef18]

hi! new to this hobby and honestly a little confused. just bought the fluval 13.5 gal tank, have the fluval protein skimmer in chamber 1, the original filtration in chamber 2 and original pump and heater in chamber 3. I am not planning on any coral but plan to stock it with as much fish as I can. I've read that the original filtration is not very good. what can I switch to and how do I set that up. also have live sand and dry rock

I think only the return pump could be upgraded, but honestly for a 13 g, the max you should have is 2 to 3 small fish or one medium sized. You really shouldn't try say anything more than that or it will be a disaster.