Sponge filter- Coarse vs Fine sponge & biomedia question

[Anomander]

Hi all,

I've bought a Superfish double sponge filter with two biochambers (pic below) to put in a 60-70 litre low-tech tank, which will be planted with Anubias & floating plants, and will eventually be stocked with some Pygmy Corydoras. The filter will be hooked up to a 500 lph powerhead with a spray bar.

I have sourced two different types of sponges that will fit the filter - one set is 30ppi Poret, the other is 20ppi (non-Poret). I am also planning to fill the two chambers with either chopped up pot-scrubbers or some Eheim Substrat Pro.

I would appreciate any advice on:

i) Would the 20 or 30 ppi sponges be the better choice?

ii) Would there be a significant difference between using pot scrubbers or Eheim Substrat in the biochambers?

Thanks for any help you guys could provide.

 

[dw1305]

Hi all,

I have sourced two different types of sponges that will fit the filter - one set is 30ppi Poret, the other is 20ppi (non-Poret). I am also planning to fill the two chambers with either chopped up pot-scrubbers or some Eheim Substrat Pro.

Either will do, the finer sponge will need cleaning a bit more regularly. I like <"Eheim Substrat Pro">, but not if I have to buy it.

The filter will be hooked up to a 500 lph powerhead with a spray bar.

<"Could you do this?"> It will give you a lot more sponge area.



cheers Darrel

 

[Anomander]

Hi Darrel, thanks for your feedback.

If I'm understanding you correctly, I could attach a sponge directly to the powerhead, but I would only be able to attach one sponge rather than two (the intake attached to the bottom of the powerhead isn't long enough for two), plus I would be losing the biochambers.

 

[dw1305]

Hi all,

I could attach a sponge directly to the powerhead, but I would only be able to attach one sponge

Yes, you would, but I use these <"big sponge blocks they sell for Koi"> etc. They are £10 for a 12" x 4" x 4" sponge with a 1" central hole 3/4 of the way to the bottom of the sponge <"Consistency Deficiency">.

plus I would be losing the biochambers.

They are really just a gimmick, the <"prime metric in nitrification"> is <"dissolved oxygen"> and the differing biological filtration media are really much of a muchness, whatever the companies that sell them might say <"Is expensive bio media worth it?">.

For whatever reason our hobby seems to suffer dis-proportionally from <"Snake oil"> salesman. Traditional apologies to @Miss-Pepper too, because it is a bit of a rant, but I've <"distilled my views"> of what I think is important in <"Bedside Aquarium">.

cheers Darrel

 

[Anomander]

You make a very interesting point, especially regarding the biochambers' redundancy. I suppose the main reason I was invested in this filter model was that I believed the biochambers would free up the sponges to do more mechanical filtration, which I've heard is often a weakness with sponge filters.

Your suggestion would also mean I am not at the mercy of my own DIY skills, since the only way my powerhead can attach to the double-sponge filter is with some superglue and silicone, and I'm not sure how permanent that fix would be in the long run.

The sponge you suggested is very welcome, but unfortunately a bit too tall for my tank. However, I have found this which is not only slightly smaller, but should also be compatible with my powerhead (Aquael Turbo 500) and therefore I could keep the spray bar and, more importantly, no need for patchy DIY!

I would go for the 30 ppi rather than the 45 ppi in the suggested link. Do you believe that one 30 ppi sponge of 5 x 6 x 20cm would be enough mechanical and biological filtration for my tank (which will have floating plants and eventually about a dozen pygmy corydoras?)

Thanks again for your input. Every time I post on here I receive really valuable information which cuts through all the noisy dross of the internet!

 

[dw1305]

Hi all,

The sponge you suggested is very welcome, but unfortunately a bit too tall for my tank.

They sell them as 4" x 4" x 4" cubes etc. as well, I just buy the big ones (it is cheaper) and cut them down to size.

However, I have found this which is not only slightly smaller, but should also be compatible with my powerhead (Aquael Turbo 500) and therefore I could keep the spray bar and, more importantly, no need for patchy DIY!

I think these are good, they are all based on on the ones that Stephan Tanner (<"Swiss Tropicals">) sell in the USA. I've got a <"lot of time for Dr Tanner"> - <"Aquarium Biofiltration - SWISSTROPICALS">.

Do you believe that one 30 ppi sponge of 5 x 6 x 20cm would be enough mechanical and biological filtration for my tank (which will have floating plants and eventually about a dozen pygmy corydoras?)

It should be absolutely fine. Nitrification in planted tanks (<"plant / microbe biofiltration">) isn't reliant on the filter in the same way it would be in a <"microbe only"> system.

cheers Darrel

 

[dw1305]

Hi all,

I suppose the main reason I was invested in this filter model was that I believed the biochambers would free up the sponges to do more mechanical filtration, which I've heard is often a weakness with sponge filters.

I use the same sponges as <"pre-filters on canister filters etc">. Once it is wet all <"mechanical filtration media"> is <"biological filtration media"> as well, <"if that makes sense">?

cheers Darrel

 

[Anomander]

Thank you for the help; I think I'll shelve the double sponge filter for use as a backup, and buy the 20cm 30ppi Poret. It should look a bit neater in the tank as well.

 

[Anomander]

Hello again, I just have a question from reading through some other threads on here.

Namely, if I have one sponge that is doing both mechanical and biological filtration, how often and how vigorously should I be cleaning it? I realise that mechanical filtration needs to be cleaned so that flow (and oxygen) is maintained for the beneficial bacteria, but at the same time in cleaning the sponge I don't want to destroy said beneficial bacteria.

Thanks again for any input.

 

[hypnogogia]

Clean it when you see flow beginning to slow down. I clean mine in a bucket of tank water and will squeeze out the water and let it reabsorb the tank water a few times until the worst detritus is out of the filter foam.

 

[dw1305]

Hi all,

how often and how vigorously should I be cleaning it?

It will depend a little a bit on the tank, but I usually give mine a swoosh around (under the tap) <"every couple of weeks">. Our <"water supply"> (in the UK) is <"relatively lightly chlorinated"> so you don't need to worry about "sterilising" your sponge <"Cleaning filter sponges in tap water">.

I don't go mad with squeezing them etc. and then I give them a dunk in the water changed tank water before replacing them. The tank water isn't for any microbiological reasons, it is just our (non-drinking) tap water has a <"water softener">, and I don't want to add any unnecessary sodium ions (Na+) to the tank.

In a planted tank you are never <"entirely reliant on the filter for nitrification"> and our filters never develop the <"thick and sticky biofilm"> that "microbe only" filtration requires.

cheers Darrel

 

[Anomander]

Thank you both!