how do you know a sponge filter is cycled

**Angelfish11788** · 12-13-2012, 03:12 AM

when it is grungy looking. I got a new sponge in my 75 soaking up the BB while I am in the process of setting up 20L betta/platy tank. So as title states, i mean it cant take as long as a filter in an un-cylced tank. I assume that it will cycle before it gets discolored by gunk. also a question to ponder, since i am using a cheap air pump; it is rated for 5 gallons and well the sponge is quite big. Will it take longer to cycle the sponge because less water is pulling through? should i get a air pump rated higher to get more suction so it filters more BB to cling.

**KevinVA** · 12-13-2012, 03:47 AM

Originally Posted by Angelfish11788

when it is grungy looking. I got a new sponge in my 75 soaking up the BB while I am in the process of setting up 20L betta/platy tank. So as title states, i mean it cant take as long as a filter in an un-cylced tank. I assume that it will cycle before it gets discolored by gunk. also a question to ponder, since i am using a cheap air pump; it is rated for 5 gallons and well the sponge is quite big. Will it take longer to cycle the sponge because less water is pulling through? should i get a air pump rated higher to get more suction so it filters more BB to cling.

Well, how does the pump perform? Does the pump have two outlets or just one? Are you only powering one bubbler with it? Are you getting a good amount of bubbles at a decent rate? It should probably take about 4 weeks to get a sponge filter cycled. I have 3 sponge filters in my 75gal. One's rated for 40 and two are rated for 10. The 10s are for QT swapping.

**Angelfish11788** · 12-13-2012, 11:06 AM

Yes to all questions. Except it only has one outlet. It works fine;,I just thought more water through quicker it would go. Thanks

**Goes to 11!** · 12-13-2012, 11:21 AM

Originally Posted by Angelfish11788

Yes to all questions. Except it only has one outlet. It works fine;,I just thought more water through quicker it would go. Thanks

+1 to Kevin.

More flow equals more food [Ammonia/TrItes] flowing past the growing BB colony but it doesn't increase the rate at which the BB develops.

In this case a higher flow rate could potentially increase the sponges capacity for BB [Over low flow] as it would keep more BB fed than a lower rate. You can't have more BB than you have food available to feed them you know?

This will work but IMO your goals would be more effectively served by a higher flow.

**Angelfish11788** · 12-13-2012, 03:02 PM

alright, i think i have a higher powered air pump somewhere, back in the day of buying all deals on craiglist i got a smal box of powerheads and airepumps somewhere i just cant find them

**KevinVA** · 12-13-2012, 03:30 PM

You can get a pretty powerful one relatively cheaply these days.

I'm using one of these in my 75gal: http://www.amazon.com/JW-Pet-Company...words=air+pump

It's pretty beastly.

**Dave Waits** · 12-13-2012, 07:04 PM

There are a lot of misconceptions about Sponge Filters and their efficiency. Actually, properly-sized Sponge Filters can out perform HOB filters as far as biological filtration is concerned.

Here's a very well-written article on Sponge Filters and how they work. Very good reading.

http://www.americanaquariumproducts....iltration.html