DIY Natureef Style Denitrator Build and Data thread...

[Northside Reef]

Actually Matt has been dosing with 50% v/v methanol and r/o since we started. To prevent confusion I've been posting the dose in pure methanol. Methanol is very water soluble and a 50% solution will not separate back out.

Mixing methanol tips:
when mixing always add methanol to water

The reaction is exothermic; it will get warm

Measure the volume of water and methanol separately then combine. When combined the total volume will decrease slightly; this is expected.

I see, that all helps. Thanks again guys.

 

[mrx66699]

Today's measurement ...cycle 3 almost 24 hr ....

Almost down to 24 hrs

 

[DRThompson]

What do you think the limiting factor is currently before the cycle can be done multiple times in a day? Is it the build-up of bacteria? or the dosing amount? Bascially do you expect to continue increasing the dosage amount until you get to the cycle time you want? or are you trying to culture enough bacteria to reach that goal? or a combo?

Bacteria is the limiting factor for cycle time. In the first few cycles we are mainly trying to grow the bacteria, so we dose more aggressively. Methanol is just the food. Eventually there will be enough bacteria to remove the nitrates faster and the cycle time will go down.

The methanol dose is directly related to the amount of nitrates in the chamber. I'm using a ratio of 3:1 (methanol:nitrates) for dosing. This is based on my experience and articles I've read. I've read wastewater treatment plants go as high as 4:1 though. However, IME 3:1 works well for the saltwater aquarium denitrater. For maint dosing we will be using just enough to take care of the nitrates. As the nitrates in the tank go down over time we will lower the methanol dose in the denitrator.

 

[lnevo]

What is the target nitrate levels you guys are aiming for once in full swing?

 

[ebonline]

MRX & DrThompson
Very nice write up and I will be following along in the thread. It seems like a pretty easy way to remove nitrates from tanks after you get it down to the 3 or so cycles (10-15%) per tank water a day. My question is when are you injecting the methanol into the denitrator tank? Is the new methanol dose going in while the flush is going on, right after flush is finished or a few minutes after finished and will you be injecting it all at once with a dosing pump at that time? Are you also dosing it into this chamber in a specific location such as the opposite end of the drain opening or does it really matter? Thanks and look forward to the progress.

 

[DRThompson]

What is the target nitrate levels you guys are aiming for once in full swing?

At the end of a cycle the nitrites and nitrates should read 0 in the chamber. Target levels of nitrates in the tank are "as low as possible"

In my 200gal system, I'm able to keep my nitrates at 2.5-5mg/L (salfert test kit) using my 12gal denitrator that I cycle 3 times per day. I dose 2ml of Methanol per cycle.

 

[DRThompson]

MRX & DrThompson
Very nice write up and I will be following along in the thread. It seems like a pretty easy way to remove nitrates from tanks after you get it down to the 3 or so cycles (10-15%) per tank water a day. My question is when are you injecting the methanol into the denitrator tank? Is the new methanol dose going in while the flush is going on, right after flush is finished or a few minutes after finished and will you be injecting it all at once with a dosing pump at that time? Are you also dosing it into this chamber in a specific location such as the opposite end of the drain opening or does it really matter? Thanks and look forward to the progress.

We dose the methanol just AFTER the flush. We dose at the opposite end as the drain but it doesnt really matter. If possible dose on the same end as the internal pump; just to be sure it gets properly dispersed.

 

[mrx66699]

What is the target nitrate levels you guys are aiming for once in full swing?

as Dave said we are shooting for as low as possible but a 0 when flushing

MRX & DrThompson
Very nice write up and I will be following along in the thread. It seems like a pretty easy way to remove nitrates from tanks after you get it down to the 3 or so cycles (10-15%) per tank water a day. My question is when are you injecting the methanol into the denitrator tank? Is the new methanol dose going in while the flush is going on, right after flush is finished or a few minutes after finished and will you be injecting it all at once with a dosing pump at that time? Are you also dosing it into this chamber in a specific location such as the opposite end of the drain opening or does it really matter? Thanks and look forward to the progress.

Just one thing to add to what Dave had stated .....you will want to wait for a few minutes after the flush pump has turned off just to let the small amount that is still syphoning out to disperse....especially if you are not doing this manually once things are automated ....make sure you program in a 10 min or so wait time period once the flush pump has turned off before you tell your controller to dose otherwise you would just be dumping some of the food your trying to feed the bacteria with....

and speaking on the draining of the system if you are building a chamber for your use DIY make sure to double the size of the drain pipe that is draining according to your input pipe so you it wont overflow while filling to flush .....I have a mag 7 filling things in a 1/2 pipe and the drain is a 1 in and mine fills right to the top about 1/4 in over the top of the bulkhead that holds the 1 in drain pipe....this is something to take into account when drilling your DIY chamber also if you are building your own make sure you allow an 1in or so above the placement of the drain hole when drilling for flush fill room...

also your drain should NOT have any piping inside the chamber like an elbow facing down into the water and then on the other side wherever you are draining it to DO NOT have it submerged in the sump ....2 things will occur a syphon could happen and drain more of the chamber than you intend and also the water coming out of the chamber is very low in o2 so you will want to have it dump near the skimmer and preferably an 1in or so above water line to allow for air intake into the fresh denitrated water..

also you do not want the fill side inside the chamber to have a pipe in it going down into the water as this will cause a back siphon when filling shuts off

 

[mrx66699]

Third cycle complete ...prolly completed sometime last night during the night ...I wasn't able to measure till now but the time is certainly getting quicker.......I'm off for a week so its time to get this dialed in to an exact time as I can measure multiple times a day for the next week .....

 

[ebonline]

Thanks for the reply! Also didn't think about the pipe information and yes I will be DIY'ing one if I decide to go this route. Can or should the drain of this denitrator go into the skimmer directly or can it just go somewhere above the water line close to the intake of the skimmer. I have access to either way since I am still in the planning stages and I know they say the best way to plumb the drain of bio-pellet reactors is into the skimmer suction. Will probably have some further questions if I decide to go this route or not but it looks fairly simple once you figure out the cycle times at the beginning. I also have access to methanol as my friend runs a drag car on methanol and he buys it by the 55 gallon drum.

 

[DRThompson]

Thanks for the reply! Also didn't think about the pipe information and yes I will be DIY'ing one if I decide to go this route. Can or should the drain of this denitrator go into the skimmer directly or can it just go somewhere above the water line close to the intake of the skimmer. I have access to either way since I am still in the planning stages and I know they say the best way to plumb the drain of bio-pellet reactors is into the skimmer suction. Will probably have some further questions if I decide to go this route or not but it looks fairly simple once you figure out the cycle times at the beginning. I also have access to methanol as my friend runs a drag car on methanol and he buys it by the 55 gallon drum.

Drain should dump above the waterline over your skimmer intake. It is saturated with Nitrogen gas and this will help it gas out.

 

[mrx66699]

Cycle complete ruff estimates 12 hrs I'm going to measure the next cycle in exactly 6hrs ......

This is the measurement of the current DT water....

Skimmer has been working overtime since the first flush.....this was cleaned on Thursday night ...

This was 9am this morning

Cheto also seems to be improving I have noticed its color is more of a darker green and its spreading out more ....normally its submerged and tumbling but I wanted a clearer photo .....

 

[SPotter]

those are great updates!!!!!

 

[bmanzie]

Looking good Matt

 

[nivram]

Matt, keep an eye on your cheato. I would expect it to die out and release nutrients back into tank as the nitrates and phosphates decrease.

 

[mrx66699]

Matt, keep an eye on your cheato. I would expect it to die out and release nutrients back into tank as the nitrates and phosphates decrease.

Ya I expect it to starve off some after nutrients are exported to a very low number but for the moment it is enjoying the cleaner water with still enough nutrients for it to thrive

 

[mrx66699]

Cycle was completed around 9 hours I was shooting for 6 but it wasn't quite there yet .....here is today's reading on the DT......moving right along nicely as we can see ...if I had to say sat reading was on the high side of 10 and today's seems to be on the closer to it side ....

Skimmer still working overtime ...skimmer is a Bubble King Supermarine 300 just incase anyone was curious....

 

[mrx66699]

Cycling around 8-8.5 hours ....here is this mornings readings on the left was the levels going in on the right are the finished results.....

 

[iTzJu]

Following on the progress on this, definitely considering trying this out on my tank as well.

 

[mrx66699]

Down to 7 hrs for cycles to complete will now be automating as its cycling 3 times a day ....still manually keeping track of finishing times this week as I'm off and hopefully by the end of the week a fourth cycle will be worked in to meet the overall goal of 4 cycles per day ....