Low oxygen concerns with just powered sponge filters

[CrashBandit05]

Hey everyone, my 29gal is finally showing zero ammonia and low nitrates so I'm getting ready to get a hopeful m/f pair of GBRs. 

I am running two double sponge powered filters on each end.  With currently one outflow above water line to help agitate the water and the other outflow as far down to move water around the mid level.

Almost the whole top is covered with 75% water spangles and 25% amazon frogbit. There's two anubias on pieces of driftwood and some java moss. 

I'm assuming this is sufficient and if the plants are growing than everything should be fine but I'd definitely like some opinions!

[kahjtheundedicated]

If there's surface agitation, it'll probably plenty for just two fish in a 29. That said, adding an air stone never hurts. Alternatively you can see if your powerheads have a spot for a venturi, which you run a tube from to above the water level, and it'll suck air down into the outflow of the powerhead.

[Beardedbillygoat1975]

That's plenty of filtration and oxygenation for stocking GBRs, could do a shoal of tetras and some corys as well. Sounds like an awesome setup! Would love to see some pics @CrashBandit05!

[CrashBandit05]

@kahjtheundedicatedI swear I saw/read somewhere you could hook up an airline to these filters but I couldn't find the information. They are aqqa brand electric powered filters.. couldn't find anything on their website either. I'll look more into airstones, thanks!

@Beardedbillygoat1975I originally got a small group of black neon tetras to help jump start the cycle and lost 3, down to 3 now. And a small group of corys, lost 1, down to 4 now. I don't know if I'll get more tetras or move them to my 9gal. I like the corys though, may get more. It's hard to pick a good top/mid schooling fish. I got a few pics but the cats tore our blinds down so the glare is awful!

 

[kahjtheundedicated]

Looks like there is an air hose fitting on top of the outlet of the filter, but not sure if it's a venturi, or if they expect you to attach an air pump to it.

But the easiest option is just to raise the outlet of one above the water line. The waterfall will increase oxygenation, but might be a little noisy. But again, you probably don't need to worry about it either way.

[Beardedbillygoat1975]

Hatchets are super underrated. You need a top for them though. 

Lemon tetras are amazing, black or red phantoms, candy canes and if you can find them keri or blueberry tetras are awesome. 

Barbs cherries are the best. Danios I like the glowlight. 
 

[nabokovfan87]

On 7/12/2022 at 10:03 AM, CrashBandit05 said:

I would suggest having a feeding ring and then having an air stone or two on a gang valve.

The filters you have might have the ability to add air, but I think you'll get a much better result with the ziss airstones and a metal gang valve.

[Odd Duck]

I’ve had fish that started to look “off” if I let the tank get too covered with floaters.  I like to keep it at no more than 75% surface coverage.  Since most floaters don’t like airstone spatter very much, you can run a floating circle of airline around the airline going to the airstone and that will give you plenty of surface agitation and still keep your floaters happy.  I like double diameter airline for my circles since it keeps the floaters better controlled.  It is much more obviously visible, though, so you’ll have to decide if you like that or not.

[Patrick_G]

Your tank look great. I was picturing something totally different when you said powered sponge filters! Those look like they’ll be great for breeding if that’s your goal with the Rams. 
 

[Guppysnail]

I use airline tubing around my airlines connected with check valves to keep open space for gas transfer. That way if I don’t get around to clearing it (like it is overgrown now) it still doesn’t obstruct. 

[CrashBandit05]

@Odd Duck thanks for that information, I will keep that in mind. Looks like I'm to the point of throwing floaters away now!

@Patrick_G thanks for the compliment! I think it would be cool to have offspring but we'll see!

@Guppysnail I sincerely appreciate the pictures! I will have to read more on airlines and their accessories, I admit I know basically nothing about it other than supplying oxygen..

 

[Guppysnail]

@CrashBandit05 I just cut a piece of airline. I either use check valves or connectors. I did not have any connectors when I set these up so I rooted about the fish room and found checkvalves to use that worked the same. The odd shape ones do not work water gets in and they sink. The straight ones work great. 

[Odd Duck]

Here’s a couple pics of double diameter airline rings in and out of a tank.  Not the same rings, obviously.  I used T connectors to join 2 rings, but I also have straight connectors that I usually use to close the loops.  Sometimes I just put loops around the airlines to control surface agitation for the floaters and keep some open surface, sometimes I keep the floaters inside the rings if I want the plants beneath them to get more light.  I wrangle the rings with suction cups and zip ties or selectively sabotaged feeding rings.

 

[Wrencher_Scott]

Don't forget you don't have to have waves/ripples for O2 in the water, many tiny bubbles will do this for you. 

In other words, you can cover the top with floating plants, glass, whatever but as long as you have lots of bubbles you will be good. 

[Odd Duck]

On 7/13/2022 at 7:48 PM, Wrencher_Scott said:

Don't forget you don't have to have waves/ripples for O2 in the water, many tiny bubbles will do this for you. 

In other words, you can cover the top with floating plants, glass, whatever but as long as you have lots of bubbles you will be good. 

The tank where the fish were “off”had a sponge filter with plenty of bubbles. Too dense of coverage (the red root floaters were literally heaping up and about 1.5” thick) was too much.  Thinned out the floaters (took out about a gallon of them) and everything was back to normal.

[Wrencher_Scott]

On 7/13/2022 at 6:05 PM, Odd Duck said:

The tank where the fish were “off”had a sponge filter with plenty of bubbles. Too dense of coverage (the red root floaters were literally heaping up and about 1.5” thick) was too much.  Thinned out the floaters (took out about a gallon of them) and everything was back to normal.

 

So are you saying 1.5" of floaters will cause O2 to go down causing the fish to seam "off"?

 

 

 

 

[Odd Duck]

That’s the only significant change I made was to reduce the floater load. It may have been more about shading out the other plants or not having enough surface exposed, but I started limiting cover after that and at least keeping a ring open and I haven’t had that same issue since.  I did a water change, too, but that was normal routine.  Maybe the bottom layer of plants was rotting (didn’t seem that way as I pulled them), but less cover was immediately better.  The floaters were really growing in that tank and I routinely pulled about a quart every couple weeks.  I let it build up a couple weeks because I was planning to give away a bunch after Snowpocalypse in Texas last year so I didn’t harvest at a couple water changes.  I learned to not let them build up too much and everything was happier.

On 7/13/2022 at 8:34 PM, Wrencher_Scott said:

 

So are you saying 1.5" of floaters will cause O2 to go down causing the fish to seam "off"?

 

 

 

 

I don’t know if it was O2 going down or CO2 building up at night?  I couldn’t tell you that.

[Wrencher_Scott]

On 7/13/2022 at 6:52 PM, Odd Duck said:

That’s the only significant change I made was to reduce the floater load. It may have been more about shading out the other plants or not having enough surface exposed, but I started limiting cover after that and at least keeping a ring open and I haven’t had that same issue since.  I did a water change, too, but that was normal routine.  Maybe the bottom layer of plants was rotting (didn’t seem that way as I pulled them), but less cover was immediately better.  The floaters were really growing in that tank and I routinely pulled about a quart every couple weeks.  I let it build up a couple weeks because I was planning to give away a bunch after Snowpocalypse in Texas last year so I didn’t harvest at a couple water changes.  I learned to not let them build up too much and everything was happier.

I don’t know if it was O2 going down or CO2 building up at night?  I couldn’t tell you that.

That is interesting for sure. 

It seems that if one has enough bubbles that it wouldn't matter what the cover is concerning the fish. You know what I mean? When you have air pumped in it doesn't matter what the cover is. You are pumping air in the water. Listless water doesn't exchange much of anything.

I will leave my Discus without opening the lid on my aquarium when I leave them for a week with the cover closed. I do this so I don't have evaporation. 

The lid/glass is pretty tight. There is one hole in the glass that I cut for the auto feeder, it's a 1/2" hole. 

I have a lot of bubbles, undergravel filter driven by uplifts and another pump running two 10" bars of air. 

Anyway, my thought is still water on the surface is next to nothing as far as O2 or CO2 exchange.

I know some keep very heavily planted tanks with no air but do use CO2. But I don't think this if for a beginner or simple fish keeper like the original poster @CrashBandit05

Lets not get ahead of ourselves I guess is what I'm saying.

[Odd Duck]

On 7/13/2022 at 9:46 PM, Wrencher_Scott said:

That is interesting for sure. 

It seems that if one has enough bubbles that it wouldn't matter what the cover is concerning the fish. You know what I mean? When you have air pumped in it doesn't matter what the cover is. You are pumping air in the water. Listless water doesn't exchange much of anything.

I will leave my Discus without opening the lid on my aquarium when I leave them for a week with the cover closed. I do this so I don't have evaporation. 

The lid/glass is pretty tight. There is one hole in the glass that I cut for the auto feeder, it's a 1/2" hole. 

I have a lot of bubbles, undergravel filter driven by uplifts and another pump running two 10" bars of air. 

Anyway, my thought is still water on the surface is next to nothing as far as O2 or CO2 exchange.

I know some keep very heavily planted tanks with no air but do use CO2. But I don't think this if for a beginner or simple fish keeper like the original poster @CrashBandit05

Lets not get ahead of ourselves I guess is what I'm saying.

I’ve found that when floaters develop into a dense enough mat the surface water turnover rate is poor and I suspect that’s what was happening in my “unhappy” tank.  I’ve had mostly red root floaters and frogbit and neither grows especially well in very small groups unless you do something to limit surface agitation and stirring/swirling of the plants on the surface.  They grow far faster if they are collected into a group or they have limited surface movement so they aren’t constantly swirling.  As they develop more of a mat and “link” together, their growth rate explodes.

[Beardedbillygoat1975]

If you don’t move the gas around the tank the bubbles don’t matter. This is why people who use co2 often put the bubbler below the outflow of a filter to get the co2 carried around the tank. If the O2 and bubbles are localized to one part of the tank that does not mean the rest of the tank has the same dissolved O2. You have to have current to pull the gasses around. Example - lakes in the cascades have issues with blue green algae blooms. The lack of current in the lake creates dead zones where the build up of co2 is much too great and the fish in those areas of the lake just drift off to a forever nap 😴 💀.