Deltec Nitrate Reactor

[Just Toby]

I thought I would share this experience with you.

I am a firm believer that if you are not changing more than 25% - 50% of your water per week with low nitrate water (or have constant drip) then you are very likely to run in to long or even short term nitrate problems.

My tank can go up by 50ppm in a week.

I have recently started running one of Deltecs reactors NFP509 and it is a lovely piece of kit BUT

You need to slowly build up the flow rate as per the very clear instructions and dose with a dosing pump to supply 2X4ml of Carbon / RO / Vodka solution.

It is VERY hard to get the drip rate right but I finally have Nitrate free water coming out of the reactor with 40ppm going in and I am ramping up the flow rate.

The other day a £7 timer for the dosing pump stuck on and drained 500ml of Vodka solution in to the reactor and then the sump which crashed the PH and slowed the bacteria to a stop, the Nitrite was mid-scale on a test kit before I spotted this and did a 50% water change - all parameters returned to normal very quickly.

I have now invested in an Aquatronica with Redox probe and PH probe to monitor and alarm if there are any issues, this also runs the dosing pump.

I will keep you all posted as to the progress.

 

[johno27]

Sounds kind of cool. But I am still a firm believer in a drip system or water changes

I assume you are still changing out water and just trying to get nitrates to absolute 0

I look forward to updates to see if you can get it running hassle free

 

[PeteLockwood]

I will write this while admitting I know zero on the subject but.. Would an IV drip bag work for dosing your Vodka?

 

[ar0wan]

My reacter is a total DIY so I don't have instrunctions on feeding
What is the recommended drip rate and frequency of vodka infusions per the literature?

edit: RTFM

 

[sponger_2]

why not just run one of those diy algae scrubbers? Way easier to maintain. Says you can do away with water changes as well.

 

[Just Toby]

Ok here goes a long reply.

I have read all of the algae scrubber thread and it does seem that they are more reliable in salt water, there have been a lot of leaks and crashes plus I would not want it to be too diy with 1000litres circulating.

The iv is a good idea but I think I have the dosing sorted now with the reliable timer, the dosing pump is 1ml per min and is a medical grade deltec pump supplied as part of the reactor kit.

The dosing rate for the vodka is 75% ro with no minerals and 25% vodka, this is dosed at 4ml twice per day beut will eventually run at around 11ml total based on 1.5 litres per min of zero nitrate water leaving the reactor. The redox probe is to monitor the orp redox and the ideal anaerobic environment is at -170mv therefore you adjust the flow and vodka to meet this.

The reactor should maintain a tank of 1000 litres (same as mine) at 0-10ppm.

My target is 10ppm max constant without the Need for water changes but I will always maintain at least 25-50% changes.

No matter what you use you should never drop the water changes as there is so much more than the nitrogen cycle to be replenished and refreshed (minerals etc...) I do not feel 100% comfortable with constant drip due to the low temps of my supply water, I am already on a meter due ti a swimming pool and my waste that is plumbed to the tank has been known to freeze in winter which could cause a flood with constant drip.

Thank you all for your interest and I will keep you all posted.

 

[knifegill]

Thought of trying deep sand bed? Testing one out right now downstairs but too soon for results.

 

[Just Toby]

Thought of trying deep sand bed? Testing one out right now downstairs but too soon for results.

I have quite a bit of experience with these and I do not believe they will ever handle the level of Nitrate produced. The deep sand beds work much better in Marine IME. You can use mracle mud etc in marine.

You know when they are starting to work as the sand starts to go black at the edges and gas bubbles form. To get the best out of them I would suggest some burrowing snails to turn over the sand. Bacteria can build up in the sand as well if not turned over. I used to use star fish in mine when I kept an Octopus.

Please let me know your results.

Update on the Nitrate today. It is below 25ppm in the tank and is coming out of the deltec at 5ppm or less, I need to reduce the redox a little more to maintain zero as I up the flow. I am calibrating the redox probe now so should be able to control things better.

It is possible to rig a solenoid up to the redox controler and as the redox goes too low if feeds a little more supply water but I have tried to keep it as simple as possible for now.

 

[earthstudent]

I have read all of the algae scrubber thread and it does seem that they are more reliable in salt water, there have been a lot of leaks and crashes plus I would not want it to be too diy with 1000litres circulating.

I run algae scrubbers on all my tanks, freshwater, marine and brackish. They are the best thing you can put on your tank IMO. Easy to maintain and do allot for the tank. Algae provides vitamins and helps balance PH and mineral levels in the water.

The first tank I tried a scrubber on was a 55g freshwater tank. I wanted to see what the scrubber could do so I had a bio tower with filter pad and the scrubber, that is it for the filter system. I have had the tank setup for almost a year and have not done a water change on it EVER. I just top it off with untreated tap water as needed. I test the water regularly and have never had (after it was cycled) any nitrite or ammonia (always 0) and nitrates are never over 10 and the water is crystal clear. This tank has green spotted puffers (not the hardiest fish) in it and started as freshwater and I have built the salt level up gradually over time (as these puffers need this) and the salt level now is up to 1.013 and I will continue to raise it until I get to full marine level. The scrubber has had no issues with this.

I just put a scrubber (a few month ago) on a 75g freshwater tank that needed frequent water changes to keep nitrates below 20. This tank now gets no water changes and nitrates are always below 10.

The algae itself adds vitamins and minerals to the water as well as balances them so from what I can tell, doing water changes to "replenish" minerals and vitamins is not needed as you will be adding water due to evaporation.

The only down side to an algae scrubber is it is a form of biological filtration, so it is a living organism and needs time to establish it self (the way bacteria needs to) and if the system dries out for to long the algae can die leaving your tank with out its needed filtration. But this is the same case with a wet dry bio tower yet people use them all the time without to many of these problems. The pump on one of my scrubbers froze up one day and I came home to a dried out algae scrubber. I got the pump working and the scrubber going again and it did not kill the algae. So if you are checking the tank one a day, I don't think you would have any problems with the scrubber dieing.

I think you should do some more research on scrubbers (or just test one out) as they are great for any tank no matter the size or salinity level. They are cheap and easy to build. I would say they are way more reliable, easier to maintain and cheaper than what you are doing now. And a scrubber for 1000L is not that big of a task, pretty easy actually. It sounds like you have the smarts to build an algae scrubber for your tank without a problem.

 

[Just Toby]

Thanks for the algae scrubber info, can you post up a pic of your design.

What is the climate like in Iowa as here anything left open to the air will have a lot of condensation / evaporation which would lead to a warped and swollen cabinet or tank stand if simply left. I wonder how it could be enclosed enough to stop this?