What I’ve Learned With Aquarium Filters

What I do know is once my tanks are established I just take the dang filters off lol. I just stick to my plants to do that job

you'll want to keep the filters, as the beneficial bacteria in the filter consumes the ammonia and nitrites. Plants will help a little bit with nitrates. And keep doing water changes.

 

I will be very interested to read the reports mentioned above.

All this talk about flow rate seems to be neglecting one thing. Flow rate in and out of the tank is not the same as flow rate across your media.

I have a 250 GPH pump pushing a four foot head into my oscar tank. But it's pushing that through a 3/4 inch pipe.

When that 250 GPH hits my sump it goes from a 1.25" drain pipe to a diffuser approximately 100 in square.

That means that the flow rate slows down by a huge Factor, as water goes across the media.


This is possible to achieve with an HOB filter, by putting an appropriately thick intake sponge of 30 PPI foam on the suction tube. This is reduces the flow considerably and at the same time adds about double to your bacterial Colony area. (Though it does nothing for the aerobic bacteria.)

I've been experimenting over the past year with various algae generators and live plant growth experiments.

I'm only having good results in the HOB filtered systems which have more: plants, algae generators, undergravel setups, and low stocking pressures etc.

But we have high nitrates and part of my motivation is to actually have the nitrates reduce when I put new water in the tank. I may have achieved some success at this on a very short-term basis but unfortunately my experiments are not well controlled.

I have 9 different tanks, in six different sizes with different filtration setups and different stocking in each one, so all my judgments and comparisons are going to be in necessarily subjective. But in general I believe that combination methods are the only good solution and that no one single method will suffice perpetually, and without water changes.

I have seen tanks which people claim have not had water changes for 6 months and they're perfectly healthy, but every one of those tanks uses the combination method of very low stocking plus lots of live plants.

When you look at them they are not basically fish keeping aquariums but they are mainly plant growing aquariums.

 

I will be very interested to read the reports mentioned above.

All this talk about flow rate seems to be neglecting one thing. Flow rate in and out of the tank is not the same as flow rate across your media.

I have a 250 GPH pump pushing a four foot head into my oscar tank. But it's pushing that through a 3/4 inch pipe.

When that 250 GPH hits my sump it goes from a 1.25" drain pipe to a diffuser approximately 100 in square.

That means that the flow rate slows down by a huge Factor, as water goes across the media.


This is possible to achieve with an HOB filter, by putting an appropriately thick intake sponge of 30 PPI foam on the suction tube. This is reduces the flow considerably and at the same time adds about double to your bacterial Colony area. (Though it does nothing for the aerobic bacteria.)

I've been experimenting over the past year with various algae generators and live plant growth experiments.

I'm only having good results in the HOB filtered systems which have more: plants, algae generators, undergravel setups, and low stocking pressures etc.

But we have high nitrates and part of my motivation is to actually have the nitrates reduce when I put new water in the tank. I may have achieved some success at this on a very short-term basis but unfortunately my experiments are not well controlled.

I have 9 different tanks, in six different sizes with different filtration setups and different stocking in each one, so all my judgments and comparisons are going to be in necessarily subjective. But in general I believe that combination methods are the only good solution and that no one single method will suffice perpetually, and without water changes.

I have seen tanks which people claim have not had water changes for 6 months and they're perfectly healthy, but every one of those tanks uses the combination method of very low stocking plus lots of live plants.

When you look at them they are not basically fish keeping aquariums but they are mainly plant growing aquariums.

I think that's a multiple half measures kind of thing. If you go all in on the single measures it will work, but most people don't want to go through full measures.

 

you'll want to keep the filters, as the beneficial bacteria in the filter consumes the ammonia and nitrites. Plants will help a little bit with nitrates. And keep doing water changes.

Nope this is how I do it. I know most don't but it works for me.

 

Nope this is how I do it. I know most don't but it works for me.

like a Walstad tank?

 

88ssinit, no I don't think that was the point.

I think the original point of the post was to introduce concepts of nitrate reduction and start a general discussion.

The method introduced was using particular brands of media, and what the manufacturer suggested on how to use it for a particular purpose.

There are other ways for nitrate reduction, such as Dr. Novak anoxic filtration concepts, which does not use Matrix or Biohome.

CerMedia has a product called Marine Pure, which is a 8"x8"x4" block of ceramic bio-media used in dumps. They also claim it can support anaerobic bacteria for denitrification at very low flow rates.

DIY denitrification coils also use very slow flow rates.

None of these setups I don't believe are designed to be the sole filtration of a tank, but part of a system working together for overall filtration and to support a full nitrogen cycle

 

I have seen the Biohome vids before, but not the Dr Novak low-flow under-sand plus bypass skimmer idea.
I endorse his idea without having done it and here's why:

I did something similar for many years, without a canister, and it was my most successful tank so far, in terms of fish longevity.

I had tiny gravel and coarse sand over a regular UGF with one lift tube and a big powerhead. The powerhead bypassed by design, to allow both strong surface circulation with low UGF flow. The rest experienced a much reduced flow. I had Silver Dollars live up to 14 years and a Plecos for 13.

Those fish could have survived years longer too, but I went on vacation and our housesitter poisoned them with love.

After seeing the Novak vid it all makes total sense. Also I want that tank!

. . . multiple half measures . . .

Well you are absolutely right there. To me, it is the belt-and-suspenders road to success, if not the road of the Nirvanaquarist. But I do see that road now.

 

like a Walstad tank?

I guess you could call it that. I do have lights on it and not just sunlight.

 

First, let me just say that I love Purigen. I had extensive BBA issues for **** near 2 years and tried every recommended approach I could; long black outs, huge and frequent water changes, big changes in lighting schedule and fert dosing routine. I even tried excel and peroxide spot treatments and picked up Flagfish. Nothing worked until I used Purigen. After about a week of use I saw a reduction in BBA and after about a month it was gone.
I read on another forum about a study that suggested that BBA feeds off of dissolved organics (they said B12, I have no idea of the accuracy of that) anywho, purigen removes dissolved organics (so they say) and my BBA issue disappeared.
Secondly I just see this as another excuse to heavily plant. Granted, I have a high-tech tank so I have to dose extra ferts but my nitrate is always low and I only have mechanical filtration (and my bag of purigen) in my filter. But really, we should all just heavily plant our tanks (low tech is easy and fun too!)
That being said I suppose that I could have anaerobic bacteria doing some of that work in my substrate as I have a custom soil mixture of about 60% clay (2") capped with sand at about 2". And no, I have not ever seen a gas pocket.
It's funny, watching that video made me test my tank, I have not done so for a very long time, this time I actually had some nitrates (5ppm). I don't know if that is from a recent rescape during my waterchange last week or if that is from those darned osmocote balls popping up all over my sand.

 

No one in my day to day life finds this interesting but perhaps someone here will (I found it very interesting), this is a picture of the underside of my tank. You can see how thick the clay is and can very clearly see the root systems of plants. I believe the discolorations are from root tabs and such.

 

. . . really, we should all just heavily plant our tanks . . .

Unfortunately I have several fish who simply trash live plants. The biggest will trash the plastic ones as well.

With those fish I am relying on algae generators to help suck the nutrients out of the water, but they are messy fish as well, and so get frequent water changes.

I've done several planted tanks but I am about to do my most heavily planted tank ever, and I am going to use the Novak method.

 

Unfortunately I have several fish who simply trash live plants. The biggest will trash the plastic ones as well.

With those fish I am relying on algae generators to help suck the nutrients out of the water, but they are messy fish as well, and so get frequent water changes.

I've done several planted tanks but I am about to do my most heavily planted tank ever, and I am going to use the Novak method.

I totally understand. My comment about heavily planted tanks is more a joke than anything as I have just totally embraced the planted side of things. I do in fact care more about the plants than most of my fish.
My very good friend of many years has a turtle tank and I throw him my trimmings knowing full well that his turtle will destroy them. I give him a hard time but it's the nature of things.