Overfiltration

[Kimber12]

Hello!

Just wondering if you can overfiltrate. I have a Fancy Goldfish in a 38L tank. I bought him to go in the pond, but he just gets beaten up and it much happier inside, so he's now an inside fish.

I'm finding that the standard filtration which is built into my 38L tanks is not suffice, and I'm getting a huge algae build up. I've been offered a new HOB that does 450L an hour - will this be too much for a 40L tank?

I only have the once fancy - approx 7cm at the moment - and a mystery snail. I was thinking of adding a few danios for company as I don't think it's fair to bit 2 fancy's in a 38L.

I don't have the option to upgrade tanks (lack of space) but can upgrade filter.

Thanks.

 

[CheshireKat]

I don't think you can overfiltrate, but you definitely can add too much water flow/current for some fish. I have an AquaClear 110 on a 25 gallon (94.6 liters), and it's a lot for the young platies and mollies, so I've added things under the outtake to block and/or lessen the outflow while still having full filtration capacity. They seem to like going in and being swept through the strong currents. I watched one last night do it over and over like it's an amusement ride.

I haven't had a goldfish in like 15 or more years, so I can't speak on that.

 

[kallililly1973]

I think your tank is too small for 1 goldfish let alone a couple danios for company I would keep up on your WC's till you can upgrade to a bigger tank. just my thoughts.

 

[Feohw]

Overfiltering is fine. There will still only be enough bacteria present as can deal with the waste of the fish in the tank and the waste will remain in there until cleaned. The algae could be from too much light or too many nitrates and such from the goldfish. My filter on my 200l tank is suited for up to 600l tanks. The flow is adjustable. Make sure flow isn't too high. A 38l (10 gallon) tank for a goldfish isn't ideal though. I'd recommend an upgrade.

 

[CindyVBPets]

Not really as long as you don't strip away the BB - except for flow and the fish/plants.. I don't know about the flow on whatever filter you have but...it sounds like a lot.

Maybe you can rig up a spray bar and spray it to the wall.You can maybe create some type of baffle, too, to break the flow a bit like they do for Bettas.

I have an Aqua Clear 20 on my 10 gallon because it's one Betta. The flow is just right for him. 100 GPH.

OTOH I put an AC 30 on my 20L and it is almost too much for that Betta. 150 GPH

You can optimize your filter media in all types of filters so that you don't generate a lot of extra flow but a lot of additional surface area (and also save money not replacing anything. And by adding a coarse sponge on the intake as a pre-filter.

I use Aqua Clears but this works in everything with space:
pre filter sponge
stock filter in the basket
bag of Matrix on top of that
bag of Purigen on top of that.

 

[Charlie’s Dad]

Filtration is the name of the game. The more you filter your water per hour the better. Your tank may be smaller than ideal for your goldfish but as long as you treat him and his water as if it is the Marriott it will be fine. Stay on top of the vacuuming of the substrate and test water values along with your water changes.

Post some pics..... Good luck!!!!!

 

[Skavatar]

I run two filters in my tanks, getting around 12x turnover rate. One of my goldfish is a fancy and he has no problems swimming in/through the current.

as far as the algae build up, it could be from too much light or too much nitrate. you can reduce the hours the lights are on or you can do larger, more frequent water changes.

 

[MicG]

I always think “over filtration” is needed if you are a lazy person. I myself have 3 sponge filters, 1 diy K1 media filter and a internal filter (15 gallon capacity). I have some plants in the tank as well and my molly fry platy fry and Bettas are having a happy life.

Because you keep goldfish, you need much more powerful filter for him. Easy way is HOB most powerful route is canister. I don’t like to hang a heavy stuff on my tank this I went internal, in the future I will upgrade to canister. So it’s personal preference. Anyway, it shouldn’t be a concern worrying too much. Have fun!

 

[goldface]

Just to be clear, algae is not a problem resulting from inadequate filtration, and, as far as filtration, there is a thing called diminishing returns. Water volume is a lot more important than filtration in your case. I would increase water changes 50 percent or more once or twice a week, and only feed once or twice a day and only a small amount each time.