Poor Man's Nutrients Control - Donovan's Nitrate Destroyer

[Levinson]

@Lasse

I would avoid siporax in a denitrator - please see here and some pages forward



Sincerely Lasse

Do you know if this applies to any media made from ceramic or just siporax?
Most value-for-money media seem to be made of ceramic nowadays.

 

[Lasse]

@Lasse

Do you know if this applies to any media made from ceramic or just siporax?
Most value-for-money media seem to be made of ceramic nowadays.

I have only experiences with siporax - do not know anything about the silicia content in other ceramics.

Sincerely Lasse

 

[Levinson]

Almost getting there. The outlet tower ended up taller than the inlet tower. It wasn't intentional but it shouldn't be a problem since the inlet is still higher than the outlet.
I am waiting for the PVC cement to cure. Will be leak testing tomorrow. I didn't cement the top caps (with lids that open by turning) yet but almost tempted to not glue them but just push fit them.
I still haven't decided on the filter media yet. I've been searching online but most I could find are ceramic media and I'm worried they might leak silicate in anaerobic condition like siporax does. Has anyone here experienced silicate leaching from other ceramic media? I really hope they don't.
I've got a ton of siporax and some rock rubbles at the moment.
Siporax will leach silicate in anaerobic condition so I'll only use some near the inlet and maybe like one near the outlet to supply silicate to my tank. I'll be using some rock rubbles but I'm not sure if I want to fill most of DND up with it. I also don't want it to supply too much trace elements like calcium to the tank, if that's even a possibility.

 

[blazn]

I was unaware that ceramic media in an anaerobic environment could allow silicates to be released. Thank you for that information!! Unfortunately, I assume this happened in my case. I use a couple types of Aquaneat branded media in my DND and I have had a minor diatom issue in parts of my sandbed, which started sometime after putting my DND into production. I'd hate to replace all of my media and start over, as it is so good at managing N03. But now knowing this (thank you!), I'd advise using an alternative media, if possible, to avoid any potential silicate/diatom issue. I recognize that the amount of silicate leaking should be finite, but do you have any idea how long it takes for the silicate leaking to reduce to the point it no longer feeds diatoms? Keep us posted, thanks!

 

[Levinson]

I was unaware that ceramic media in an anaerobic environment could allow silicates to be released. Thank you for that information!! Unfortunately, I assume this happened in my case. I use a couple types of Aquaneat branded media in my DND and I have had a minor diatom issue in parts of my sandbed, which started sometime after putting my DND into production. I'd hate to replace all of my media and start over, as it is so good at managing N03. But now knowing this (thank you!), I'd advise using an alternative media, if possible, to avoid any potential silicate/diatom issue. I recognize that the amount of silicate leaking should be finite, but do you have any idea how long it takes for the silicate leaking to reduce to the point it no longer feeds diatoms? Keep us posted, thanks!

Thank for the feedback. Judging by your experience, it sounds like silicate leaching from ceramic media other then siporax could be a thing.
From what I've read (mostly Lasse's posts) , the silicate leached from siporax seem to be constant and not something you'd expect it to stop. I think Lasse ended up replacing them (in his case it wasn't DND though).
It seems most media sold are made with ceramic and it sucks. I might end up using just rock rubbles but I run invert only no corals tank and I'm worried about the low pH in anaerobic zone dissolving the rubbles and elevating calcium and other elements too high. I'm not sure if it's something to be worried about though.

 

[Levinson]

I finally got it connected and dosed a little bit of MB7 today.
I ended up filling the left tower with siphorax on top, bio sphere balls (they are also ceramic but I hope they don't leach salicate) all the way down, and the right tower with rock rubbles.

 

[blazn]

Sounds like a good setup for your media. Keep us posted as to your results and enjoy the ride!

 

[Levinson]

How have your experiences been with your phosphate levels? Did carbon dosing into DND have any impact on your phosphate levels? From what I've read, generally (not always), carbon dosing seem to reduce nitrate at a higher rate than phosphate so the reduction of phosphate is often limited by the nitrate level. Has this been the case for those who use DND?

 

[blazn]

As research had indicated that I shouldn't expect much, if any, measurable PO4 reduction from a DND, I've used GFO to handle that. I do not believe that the DND (or carbon dosing in general) has much effect on PO4.

 

[Levinson]

I have no way of testing for silicate level but I suspect it is rising after I've installed DND. The sponge growth has increased significantly.
My guesses are,
1. since I've placed some siporax on the top part of the water inlet tower (thinking that part won't be anaerobic and therefore won't release any silicate) so silicate could be leaching from that, somehow. Maybe the flow is so slow that anaerobic zone has formed close to the top?
2. Or it could be other ceramic media I have in the DND, which are mostly bio-spheres and a few yellow square ceramic stick things with a hole in the centre. Personally, I don't think it's the bio-spheres and suspect the square ceramic stick things more.

I'm not sure if I should be worried about this or not. I can't find any test kit for silicate for sale where I live and if I have to get one I will need to import it myself (meaning $$$).
I hope the silicate level doesn't get out of hand. Also hope the growing sponges contribute to the nutrient control.

 

[Levinson]

Or maybe it only releases when I carbon dose?

 

[blazn]

Or maybe it only releases when I carbon dose?

Yes, the result of carbon dosing will definitely increase sponge growth, as they consume dissolved organic carbon. I had numerous cryptic sponges appear when I was ramping up my vodka dosing during the initial stages of my DND, prior to reaching my maintenance dose rate. That only lasted a few weeks, while the carbon input was high. I still have more cryptic sponges than prior to carbon dosing, but not the vast number I had during that period. I wouldn't be concerned about silicates being the source of your sponge growth at this point.

 

[SPS clown]

Hi All - ive been running my DND for about5 weeks now and havent seen any changes yet. No changes to nitrate test at any point incl 30 minutes after dosing vsv. My dnd is 3” pvc, both towers are 24” tall. I dosed 250ml of mb7 (over weeks)- thought i might have had a bad bottle so i just started dosing a bottle of dr tims, today was day 3.

Im dosing vsv 4x a day. 2 ml each dose (auto doser)

Flow rate is about 1ml/second, very slow steady stream.

Internally i used mostly ceramic rings from a few brands and some balls mixed in there. On the inlet side i put a small piece of poly prefilter. I also tossed 3 or 4 small pieces of rubble from my sump in there…

Thoughts? Thanks for any feedback, really wanna get this running…

 

[Levinson]

I had an issue with air getting into the DND through the outlet tube when there was a change in the flow rate, the flow rate was inconsistent or too low.
I added a bend at the end of the outlet tube with an elbow facing upwards so the effluent overflows out of the tube. That way, no air would enter the DND even when the flow stops. The outlet tube would have some water remaining in the bend blocking the tube.
Not sure if this would be helpful for the others but it worked for me.

 

[MBruun]

I having silicates leaching from the ceramic media in my DND as well, but see it as a positive thing as it support the growth of fungus, and the max number from the ICP-MS tests have been 184 μg/l (now around 140 μg/l)

 

[blazn]

Hi All - ive been running my DND for about5 weeks now and havent seen any changes yet. No changes to nitrate test at any point incl 30 minutes after dosing vsv. My dnd is 3” pvc, both towers are 24” tall. I dosed 250ml of mb7 (over weeks)- thought i might have had a bad bottle so i just started dosing a bottle of dr tims, today was day 3.

Im dosing vsv 4x a day. 2 ml each dose (auto doser)

Flow rate is about 1ml/second, very slow steady stream.

Internally i used mostly ceramic rings from a few brands and some balls mixed in there. On the inlet side i put a small piece of poly prefilter. I also tossed 3 or 4 small pieces of rubble from my sump in there…

Thoughts? Thanks for any feedback, really wanna get this running…

It sounds like you've got your DND setup correctly, so I expect you only need some minor tweaking and a bit of time. Adding another bacteria source (Dr. Tims) was probably a good move. I only dose vodka & don't have experience with vsv, but when I was ramping up my initial phase of my DND, I maxed at 20ml/day of vodka. My maintenance dose (after my DND was fully functional) is 4-5ml/day of vodka. So, I would think that you may want to ramp up your vsv dosage during your initial phase. Whatever you do, be patient, you'll get there and it's worth it!

 

[SPS clown]

It sounds like you've got your DND setup correctly, so I expect you only need some minor tweaking and a bit of time. Adding another bacteria source (Dr. Tims) was probably a good move. I only dose vodka & don't have experience with vsv, but when I was ramping up my initial phase of my DND, I maxed at 20ml/day of vodka. My maintenance dose (after my DND was fully functional) is 4-5ml/day of vodka. So, I would think that you may want to ramp up your vsv dosage during your initial phase. Whatever you do, be patient, you'll get there and it's worth it!

Ok - thanks!

I put a loop in my effluent line to prevent any air from going in this morning.

Im going to increase my vsv dose. Its mostly vodka, i took a shot of it to see how bad it was (very very bad) and then topped it with my remaining redsea phosx

I increased the flow rate to about 3ml/second

 

[piranhaman00]

Has anyone used a different way to get water into the reactor besides using a dedicated pump? Every pump I try eventually loses flow and stops trickling. I tried a gravity flow but same thing happened. I’m using RO tubing, what are others feeding the reactor with?

 

[twentyleagues]

Has anyone used a different way to get water into the reactor besides using a dedicated pump? Every pump I try eventually loses flow and stops trickling. I tried a gravity flow but same thing happened. I’m using RO tubing, what are others feeding the reactor with?

Years ago I purchased one of something just like this, not sure they are still on the market or not. But I had the same issue with the supplied pump. I used a dosing pump to fix the issue with mine. Worked like a charm after wards. Just need to make sure its continuous duty and adjustable.

 

[Levinson]

I

Has anyone used a different way to get water into the reactor besides using a dedicated pump? Every pump I try eventually loses flow and stops trickling. I tried a gravity flow but same thing happened. I’m using RO tubing, what are others feeding the reactor with?

I used a t split from the return pump.