Surface bubbles around HOB filter

[UrbanDryad]

This photo is from a Superfish Scaper 45 tank with modified HOB filter, which was scaped, planted, and filled on the weekend. The only creatures in there are a few snails who came over with the plants.



The main modification was probably getting rid of the surface skimmer and adding a pre-filter sponge, but I also filled one cartridge with coarse foam and then added a mesh bag of pre-cycled biological filtration media, which I capped with one of the fine filter pads in order to "polish" the water. I've rinsed it (in dechlorinated water) a few times already as it was getting very dark!

Should I be concerned about this? Is this just what happens without the skimmer, or a result of the agitation from the hob, or does it indicate a problem with the water, or something else?

 

[Disaronno]

Looks like just a trickle of water flow is coming from the filter? I'd assume the bubbles are trapped underneath a layer of biofilm as a result from lack of surface agitation.

 

[bazz]

I've experienced a scenario like this in the past due to the over use of root tabs. You have only just set this tank up, I don't suppose you are using Amazonia or Tropica substrate? Whatever the cause, I think water changes are the way forward.
Cheers!

 

[The Miniaturist]

I upgraded one of my tanks last week, the new one uses a hob-style trickle filter.
I used fresh sand, no root tabs, added the old filter media to the new filter & replanted most of the plants plus new ones.
After setting it running I noticed bubbles like yours at the surface. They had mostly disappeared after 48hrs & I put it down to air coming out of the substrate as the sand settled.
None of the newly returned fish (a small group of sparkling gourami & a few pygmy corries) showed any signs of distress & have settled down well.
I would agree with @Disaronno, your filter flow does seem weak, perhaps there is too much media in there obstructing the flow. Mine has a coarse but large sponge on the inlet pipe, I imagine if it were too fine the pump would struggle to draw enough water through.

 

[UrbanDryad]

Aha - the pump was turned down to the lowest possible setting, as the high flow was seriously disturbing my substrate! Plus I'm intending to keep a betta in this tank, so I wanted to see what the low flow setting was like. I turned the pump up to the highest flow setting overnight and the bubbles have now mostly dispersed. 🙂 It seems that just setting the pump to very low flow may not be the best long-term solution for water quality, so I'll look into setting up some kind of baffle so there isn't such a concentrated waterfall. Thanks for the advice everyone 🙂 And @bazz I'm using Fluval stratum, which I know will leach a bit - I did start cycling it before adding it to this tank, but I'll check the parameters shortly just in case there's an excess of anything.

 

[_Maq_]

I'm intending to keep a betta in this tank

For bettarium, you certainly do not want a nutrient rich substrate. You want to keep levels of mineral and organic pollution low to keep betta healthy. You certainly don't need an external filter for that, yet you need to cover the tank with glass - because bettas use labyrinth and the air above the surface should be humid and just as warm as the water. Bettas need 27 °C. You certainly want to feed the betta very sparingly to keep the water unpolluted, and no added biological filtration is required - the substrate will handle it. You certainly don't want to make the water moving much because bettas hate it. At the same time, you certainly want to mix your water vertically because a heater is a must when keeping a betta. Perhaps the best solution is a small internal pump running for 5 minutes every hour.

 

[UrbanDryad]

For bettarium, you certainly do not want a nutrient rich substrate.

Why so? My understanding is that betta naturally live in heavily vegetated waters with rich soil/mud underneath them, and so in the home aquarium will do best in heavily planted tanks with nutrient-rich substrates to support this level of greenery. I hope I don't sound ungrateful for the advice, but I've done quite a lot of reading about best practice for betta keeping and not encountered this perspective before, so would be really curious to see citations for this if you've got them. 🙂

You want to keep levels of mineral and organic pollution low to keep betta healthy. You certainly don't need an external filter for that, yet you need to cover the tank with glass - because bettas use labyrinth and the air above the surface should be humid and just as warm as the water.

Re: the external filter, it's what came with the tank, and I'd prefer to modify it rather than waste it. Re: coverings, I've made a lid for the tank, using polycarbonate twinwall - I just removed it for the photographs above, in order to show the bubbles.

Bettas need 27 °C.

His current tank is heated and I will add a heater to this tank before he moves over, but in the meantime my water temperature is naturally at around 27°C due to the ambient warmth from the current weather. 🙂

You certainly want to feed the betta very sparingly to keep the water unpolluted, and no added biological filtration is required - the substrate will handle it.

I am keeping an eye on his food, and am feeding him based on the shape of his belly - he does a lot of foraging for invertebrates so he's finding some of his own food within the current tank. Re: biological filtration, the Biomax came as part of a job lot of fishkeeping equipment, and while it might not have been necessary in a mature tank, I thought it was prudent to use additional biomedia to help with seeding the correct bacteria.

You certainly don't want to make the water moving much because bettas hate it. At the same time, you certainly want to mix your water vertically because a heater is a must when keeping a betta. Perhaps the best solution is a small internal pump running for 5 minutes every hour.

I know he wants slow-moving water, which is why I set the flow so low. I'm going to look into a methods of setting up a baffle to reduce the flow, but perhaps in the meantime (or in addition) I could put the pump for this filter onto a timer. 🙂

 

[_Maq_]

My understanding is that betta naturally live in heavily vegetated waters with rich soil/mud underneath them, and so in the home aquarium will do best in heavily planted tanks with nutrient-rich substrates to support this level of greenery.

It is not advisable to transfer observations from nature to our tanks without a second thought.
Bettas are sensitive to many parasites, the more so their selected forms. Their natural aggressiveness is in part a natural defense against spreading/sharing parasites.
We cannot emulate the habitat of a ditch around the rice field because such a ditch is a part of a much larger biotope with diluting and self-cleaning properties. Predators and parasites (of bettas) also contribute to maintaining the balance. We don't want our fishes sick and certainly don't want to copy their mortality rates existing in natural habitats. That's why it's reasonable to keep the tank "lean" - lean in nutrients, microbes, and organic compounds.
Lush vegetation is of course crucial to tank's well-being (and bettas like it) but the notion that it requires nutrient-rich substrate is wrong. Nutrient-rich substrates are not advertised because plants need them but because they can be sold for a price much higher than sand, and repeatedly (wile the sand is re-usable, "eternal").
Aquarists should be always aware that manufacturers of aquarium stuff are not here to help us but to make profit.

 

[UrbanDryad]

I agree that it is impossible to replicate all the conditions of a creature's natural environment in a home enclosure, and indeed that a lot of aquarium products are profit-motivated (e.g. the disaster that is cartridge filtration). But, just to be clear, it seems like what you're saying is that nutrient-rich substrate is an unnecessary expense and incurs more risk of an imbalanced tank, rather than something actively harmful? From your initial phrasing of "you certainly do not want", it sounded like you were making a dire warning against it.

Even as a newcomer to this forum, I've seen you express your enthusiasm for sand-based tanks quite often, on a number of different threads. Have you made a "masterpost" anywhere where you lay out your reasoning, methodology, results, and so on? Or a journal? I checked the Articles forum and your profile and couldn't find anything. I'd be really interested to read about your approach (but I think the full details are a little beyond the remit of this particular thread).

 

[_Maq_]

Have you made a "masterpost" anywhere where you lay out your reasoning, methodology, results, and so on? Or a journal?

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[UrbanDryad]

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Thank you! I've bookmarked this comment so I've got easy access to all your threads. This looks like a lot of really interesting reading material 🙂 Have you considered putting these links somewhere in your signature or profile?