DIY "Anoxic Filtration System" eliminates nitrates? Anyone tried this?

[lastflea]

For the most part I think people are on the API Master.

I'm still cycling and about 1 month in. 1ppm ammonia gets devoured in a few hours and nitrites rocket to 5ppm and above. Nitrate peaked at 20ppm a couple weeks ago, but doesn't go higher than 10ppm now. I've done 5 100% water changes to keep my nitrites from stalling the cycle. Only adding 1ppm ammonia each day to also keep nitrite under control. 100% water changes (including sump) now every 3rd day. Have to say, this is the most brutal cycle I've done.

I have two large baskets at 12x12x6", no outer casing. Just craft mesh. They're certainly dealing with the ammonia, but looking forward to the nitrite munchers coming into full force....

[Pices]

I’ve had my baskets running 9 wks but haven’t posted results because I am still doing 75-80% wc’s every other day. This morning is 2nd day without wc so I tested:
Ammonia-0, Nitrite-0, Nitrate-10
Should add:
I didn’t do plenum due to going back to bb 3 wks ago.
I finished treatment with metronidazole 3wks ago which could have had an effect on baskets.
Could be water flow problem as I have baskets sitting on bottom of sump. Weekend project will be to raise them a little off the bottom a bit.
Patty

[Pices]

Forgot to add that I did daily 50% wc during metronidazole treatment...

[lastflea]

If you can cut pvc piping in half, down the length, that makes an excellent support. Doesn't need attaching and runs the whole length of the basket.

I'm wondering if I have a flow problem, but a different kind. My return pump is only 3000l/h, which including sump is only about 4 times my tank volume. Anyone think this is an issue?

[Tshethar]

I'm wondering if I have a flow problem, but a different kind. My return pump is only 3000l/h, which including sump is only about 4 times my tank volume. Anyone think this is an issue?

Honestly, I have no idea, but I do think that whatever we can do to figure out optimal flow rates could help with the design. My intuitive feeling is that we're more likely to have too much flow rather than too little, though there is the need to get the ammonia from the tank in the vicinity of the baskets so the molecules can be attracted into the inner zones. But with most denitrification systems, and also in Dr. Novak's description of the plenum, the flow rates one aims at are very low. I think if one ended up pushing too much oxygenated water through the baskets, one would never have oxygen-starved conditions in the center, which is what is necessary for anoxic conditions. Otherwise, the bacteria don't need to "steal" their oxygen from nitrate molecules.

When Novak was talking about water movement in the tank substrate using the plenum, he said something like 1-2 gallons per day of movement is ideal in his 65 gallon tank! That said, he and others have baskets sitting in sumps where obviously lots of water is at least passing around them. Seems to me the bypass is critical, and that is better to err on the side of less flow than too much. (Also seems like not that much of large koi ponds are being cycled through the anoxic filter either.) But really, I'm not sure how one would figure out what is a good rule of thumb--interested to hear what others might say.

[lastflea]

Here in lies the problem Al mentioned about too many variables. Perhaps the biggest two would be flow rates and basket sizes. Possibly basket sizes being much more a factor. My two are pretty big, but I’ve ordered some more Flourite. I already have six 20kg bags of litter. I bought in bulk to save a few quid...

[shime]

Some of my info if it helps
On my most stocked tank i have currently 7 young adults. 5.75-6.5"s.At one time i had 9 adults in there. These guys are fed 5 times a day on straight beefheart. This is a 40 gallon breeder with 5 5" baskets. 550gph pump.
I kept the baskets the same size as Dr Novaks. 4-5" since it worked for him. I used these https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Ive also used the square version 5" baskets that Dr Novak used as well.

I chose to go with a fishless cycle at first to see if it would work and at one time i had 20 baskets in the 40 gallon breeder. 10 baskets were in 2 overhead sumps ( 5 in each) and 10 in the tank. This tank had 2 550 gph pumps working it and it had a pretty intense current in the tank lol. At one point in the tests during this fishless cycle it filtered about 10-15 ppm nitrates in a day, possibly more.

[lastflea]

Hmmm, so it's possible mine are too big? I can't remember who said it, or where, but I read that you can't go too big with BCB's. I've posted a question to one of Novak's videos. Hopefully get a response.

Thanks for the info

[lastflea]

Hmmm, so it's possible mine are too big? I can't remember who said it, or where, but I read that you can't go too big with BCB's. I've posted a question to one of Novak's videos. Hopefully get a response.

Thanks for the info

[Pices]

If you can cut pvc piping in half, down the length, that makes an excellent support. Doesn't need attaching and runs the whole length of the basket.

I'm wondering if I have a flow problem, but a different kind. My return pump is only 3000l/h, which including sump is only about 4 times my tank volume. Anyone think this is an issue?

I liked your pvc idea, but it would raise the bcb’s out of the water in my sump. Used plastic grate seen here. Also finally learned how to use the “reply with quote button correctly! Well let’s see...

[lastflea]

lol Patty..... We all learn from this amazing forum, one way or another...

Breaking news on my cycle. Nitrites have finally stopped increasing. Three tests today after 1ppm ammonia added, twice. Nitrite still reads 2ppm.

I realise cycling a tank is no big deal, but I can honestly say, been a real slog with the BCB's. Not sure if I'm close to the end, but fingers crossed...

[Jenene]

Hmmm, so it's possible mine are too big? I can't remember who said it, or where, but I read that you can't go too big with BCB's. I've posted a question to one of Novak's videos. Hopefully get a response.

Thanks for the info

I was thinking the same thing along with water flow that could possibly be too slow. I have two smaller baskets combined to make one big one. It’s in the refugium with only an inch around the sides. Watching water around it barely moving makes me wonder how it’s even penetrating the basket.
Thinking just adding more baskets to the main tank will help like everyone has mentioned. I have everything I need in the house except for time. Finding it today. Extra time in the day is the one thing you can’t just order on Amazon.

[Pices]

lol Patty..... We all learn from this amazing forum, one way or another...

Breaking news on my cycle. Nitrites have finally stopped increasing. Three tests today after 1ppm ammonia added, twice. Nitrite still reads 2ppm.

I realise cycling a tank is no big deal, but I can honestly say, been a real slog with the BCB's. Not sure if I'm close to the end, but fingers crossed...

I’m crossing my fingers for you Rob. How long have your bcb’s Been cooking? I’m too lazy to look back, ha ha
Patty

[Pices]

I was thinking the same thing along with water flow that could possibly be too slow. I have two smaller baskets combined to make one big one. It’s in the refugium with only an inch around the sides. Watching water around it barely moving makes me wonder how it’s even penetrating the basket.
Thinking just adding more baskets to the main tank will help like everyone has mentioned. I have everything I need in the house except for time. Finding it today. Extra time in the day is the one thing you can’t just order on Amazon.

Jenene,
Has this brought back memories of the miracle mud fiasco for you? It has crossed my mind a time or two...at least if it doesn’t work, it won’t be as bad/time consuming as taking that mud out. I took the baskets out yesterday to place grates and the dust stayed in the sump and cleaned up pretty quickly.
Patty
Patty

[lastflea]

I’m crossing my fingers for you Rob. How long have your bcb’s Been cooking? I’m too lazy to look back, ha ha
Patty

Roughly four weeks. Maybe just under. So if six weeks is the approximate time frame, then I guess I'm just being impatient. Understandable though. Haven't had a tank running for about 2.5 years.