119 replies to this topic

[Trekrider]

The electronic meter would be a Redox meter with a special probe that is designed to handle pressure. You can get the probe separately by Aquamedic (if you already have a redox meter) and this will attach to the Aquamedic nitratereductor.

They also make a computer controller for the system but it is pretty expensive - about $600 - $700 I think.

Tim, I see you are using the 400 on a 500l tank, do you think this may be why your Nitrates aren't lower?

Barry

[Cawdor]

Tim, I see you are using the 400 on a 500l tank, do you think this may be why your Nitrates aren't lower?
Barry

Barry, that's correct. The unit, given the low flow rate, can't turn over that much volume. That being said, it has made a big difference. Can it reduce nitrates to zero in my tank? No, the tank is too big. Am I happy with 10ppm? You bet

[Trekrider]

Barry, that's correct. The unit, given the low flow rate, can't turn over that much volume. That being said, it has made a big difference. Can it reduce nitrates to zero in my tank? No, the tank is too big. Am I happy with 10ppm? You bet

Thanks Tim, I would be happy with that as well I guess my loading can't be that high as I only had 20ppm before my last water change after 2 weeks. I will continue to monitor and put one of these on my Christmas wish list. Dear Santa ......

[Trekrider]

I described this unit to 'the boss' tonight and she only interrupted me twice with the question "how much" After I explained how it meant you use less water (saving water and cost) and how less frequent water changes also saved electric as you don't have to heat the water back up to temperature afterwards (I think I forgot to mention the little pump that's on 24/7) she asked when I was going to get one. Apparently I'm not very subtle about these things. She also wanted to know if I needed one for each of the tanks (4) - of course not dear - well not straight away. She did pose one question though - if reducing the Nitrates to a very low level means little or no algae, what do the catfish eat? I did say that they feed on left over food, algae wafers and fresh vegetables but didn't factor in this additional cost but I think I got away with it.

[Cawdor]

Well played Barry
I would suggest you buy one first to try out on one of your "problem" tanks, a tank that has usually fairly high readings. See what the different is after 8 weeks. If you're happy, buy more
Remember that you do NOT get a pump with it that pumps water into it - it's meant to run off the outgoing hose of a canister. The pump that is included in the head of the unit just stirs the water inside the unit.
Don't worry about your catfish - they will eat scraps and wood. You can always chuck some algae wafers or zucchini in if you're worried.
The only thing to control is the drip rate, I worked out about 2-4 drops per second should be good. Any less and it may stop dripping as the pressure isn't high enough.
get some nitrate readings before and after a waterchange so you know what the normal values are. Then continue your waterchanging regime and see if after 4-6 weeks you see a difference. After 8 weeks the bacteria should be fully established and you can experiement with increasing the time between waterchanges.
Also keep an eye out for any behavioural changes of your fish as an indicator that something may be off.
Good luck!

[Trekrider]

Well played Barry
I would suggest you buy one first to try out on one of your "problem" tanks, a tank that has usually fairly high readings. See what the different is after 8 weeks. If you're happy, buy more
Remember that you do NOT get a pump with it that pumps water into it - it's meant to run off the outgoing hose of a canister. The pump that is included in the head of the unit just stirs the water inside the unit.
Don't worry about your catfish - they will eat scraps and wood. You can always chuck some algae wafers or zucchini in if you're worried.
The only thing to control is the drip rate, I worked out about 2-4 drops per second should be good. Any less and it may stop dripping as the pressure isn't high enough.
get some nitrate readings before and after a waterchange so you know what the normal values are. Then continue your waterchanging regime and see if after 4-6 weeks you see a difference. After 8 weeks the bacteria should be fully established and you can experiement with increasing the time between waterchanges.
Also keep an eye out for any behavioural changes of your fish as an indicator that something may be off.
Good luck!

Thanks Tim, I was thinking of trying one on my 6' tank first then possibly my Cichlid tank but no more. I was aware of the pump problem from your earlier posts but as I have two canisters this shouldn't be a problem. I also wondered if you could use the output from an internal filter.

When you replace the deniballs you obviously have to open the unit up, does the in-rush of oxygen kill the bacteria so that you have to start the process all over again? By the way Aquatic life sell 0.8lt of deniballs for $54.25 - or at least they would if they weren't out of stock! They do have 5lt for $270 and 150g powder for $21.40.

When you started yours up how long did you leave it running before turning on the water flow?

[Cawdor]

You can use any output really, just a matter of doing a bit of DIY as I have done. As long as there's a pump you should be able to connect the unit to it somehow.

I have been told the Deniballs can last beyond 12 months and you do get a full set with the Aquamedic 400. The bigger models don't come with those balls.
I don't know what happens when you open up the unit to change the balls - haven't really looked into it. I assume that there may be a slight reduction of the slime due to oxygen but I think it's really a minimal impact.
I guess we'll see when the time comes!

I set mine up according to what Docfish said - I left the unit running with all valves open for a week. This is so that a bit of detritus can accumulate in the unit which later on helps the anaerobic bacteria to grow - or so I understand. After a week I closed the valves to a point where I get about 2-3 drops per second coming out. After a few days I could already see the slime forming and now it's all slimed up
I found that with my setup I have to increase the output slightly otherwise the unit may stop dripping after a while if the output is too low.
I will experiment a bit to see if a different valve setup can make a difference.
The manual is quite well written and worth a read.

[Trekrider]

I set mine up according to what Docfish said - I left the unit running with all valves open for a week. This is so that a bit of detritus can accumulate in the unit which later on helps the anaerobic bacteria to grow - or so I understand. After a week I closed the valves to a point where I get about 2-3 drops per second coming out. After a few days I could already see the slime forming and now it's all slimed up
I found that with my setup I have to increase the output slightly otherwise the unit may stop dripping after a while if the output is too low.
I will experiment a bit to see if a different valve setup can make a difference.
The manual is quite well written and worth a read.

It was reading the manual that caused me to ask - it says that for an existing aquarium you need to leave it for 8 to 14 days, feeding it once per day with 1 denimar tablet and then to check the nitrite has 'dissapeared' before turning on the water flow. I can't see a post from Docfish about starting it up - only about the redox measurement.

[Cawdor]

Docfish PMed me that info - he said it's different from what's in the manual but it seemed to work for everyone. I haven't used the powder to feed the unit, I just followed Doc's instructions and got slime forming very quickly.

It was reading the manual that caused me to ask - it says that for an existing aquarium you need to leave it for 8 to 14 days, feeding it once per day with 1 denimar tablet and then to check the nitrite has 'dissapeared' before turning on the water flow. I can't see a post from Docfish about starting it up - only about the redox measurement.

[Trekrider]

Docfish PMed me that info - he said it's different from what's in the manual but it seemed to work for everyone. I haven't used the powder to feed the unit, I just followed Doc's instructions and got slime forming very quickly.

Thanks Tim, That makes it clear - the manual says to feed once a day for 4 to 6 weeks but clearly yours is working without doing that.

[Scat]

Hey Tim

Am interested to how your setup is going now ?

Have been reading in some discus books i have some breeders in germany use this on their juvie tanks with good results.

I would be interested if one of these would be effective on a 3x2x18 (or what size would i need ?)and rather than having to water change daily for discus juvies i could use one of these and still change once per week and reap the same benefit ?

Thanks
Craig

[Cawdor]

Craig, the unit I have is now well and truly established. It should be fine on your tank, I have it on my 6x24x18. I now change the water in that tank once a month and nitrates now sit at around 10ppm and go up to 30ppm just before the water change. Before, I could not get them below 20ppm and they would go as high as 60-80ppm after two weeks.

I'm happy with the result. I find that I do need to adjust the water flow daily but I'm working on a better valve system to reduce that.
If you're in the area you're welcome to come and have a look if you want. It looks pretty slimy and gross in the unit but that's exactly what you want!

[Scat]

So you think it would cope with 4-5 times per day feedings then and once per week water changes ?

Cheers
Craig

[Cawdor]

Depends entirely on how many liters of water, how much water you change and how many fish you have and how much you feed. As you can see there are lots of variables!
The unit I have is rated for 400L and seems to cope fine with just over 400 from my tank. I have just over 20 grown fish in there which I feed once daily. My water change after 4 weeks is roughly 50%.

[dazzabozza]

Resurrecting this thread considering I bought one (400 model) on Sunday for my 330l reef tank This tank doesn't get water changes as often compared to my freshwater tanks. Most coral are sensitive to high nitrates so I thought this would be a worthwhile investment.


Have been running the unit at roughly 4 drops per second. In a few days it already has minor slime build-up.

I did some water tests today and here are the results -

Water from tank
Ammonia 0ppm
Nitrite 0.25ppm <---- this is out of the norm for this tank which led me to test the output water from the denitrator.
Nitrate 40ppm
pH 8.0


Water from Denitrator output hose
Ammonia 0.25ppm
Nitrite 0.50ppm <---- this would explain the more diluted nitrite in the aquarium.
Nitrate 10ppm <---- found this interesting. Either the unit is breaking down the nitrates already and/or the test kit (APi) is giving a false reading. From the manual "Caution! Most nitrate tests are disturbed by high nitrite concentrations!"
pH 7.2 <---- unexpected!!!


"Nitrite in the outlet of the filter. If the outlet of the filter contains high amounts of nitrite, the feeding rate is
too low. Increase the feeding (add 1 Denimar tablet per day) or lower the flow rate. In most of those cases, the
redox potential is too high (above -50 mV)."

I've since turned down the drop rate to 1-2 drops per second.


Thoughts? Should I be feeding using the tablets also?



Daz

[Cawdor]

Dazza, at this stage I would not expect any impact on your nitrates since the unit has only run for 4 days.
When you can see the slime covering most deniballs that's when your readings should start to get lower. At least a couple of weeks I'd say.

What makes me skeptical about the test kit is the ammonia reading...if there's none in the tank there should be none coming out of the unit. Nothing in the unit produces ammonia.

[Mr_docfish]

pH 7.2 <---- unexpected!!!
Thoughts? Should I be feeding using the tablets also?
Daz

The anaerobic activity will release the excess H+ in the form of an acid as it consumes some of the products in the unit...some de-nitrification my be happening at this stage... this will change as it settles in.... ...

No need to feed them any more as you have the Deniballs in there... same as the tablets....what you have done in terms of slowing the flow is correct... things will change as the unit settles in, so be prepared to fiddle a fair bit for the first few weeks until this happens... you can PM me if there are any concerns

Oliver

[dazzabozza]

What makes me skeptical about the test kit is the ammonia reading...if there's none in the tank there should be none coming out of the unit. Nothing in the unit produces ammonia.

Perhaps it has something to do with ammonia arriving from the tank into the unit and then getting trapped (due to the slow flow rate). Since their's no bacteria within the unit to break down the ammonia it's still present. Similar to any new biological filter cycling. Just a guess

The anaerobic activity will release the excess H+ in the form of an acid as it consumes some of the products in the unit...some de-nitrification my be happening at this stage... this will change as it settles in.... ...

No need to feed them any more as you have the Deniballs in there... same as the tablets....what you have done in terms of slowing the flow is correct... things will change as the unit settles in, so be prepared to fiddle a fair bit for the first few weeks until this happens... you can PM me if there are any concerns

Oliver

Thanks Oli. I'll continue to monitor it.

[Sazabi]

I bought one (400 model) on Sunday for my 330l reef tank :)Daz

How much did it cost overall?

[dazzabozza]

I'd say be prepared to spend anywhere from $250 - $300. You may need to buy a small powerhead / dosing pump and a few bits n pieces which is why the price varies. Give Aquotix a buzz or PM for a quote.