Aquarium project - Page 1
Forum section: electronics / general

author: akis
author_rank: Frequent Contributor
timestamp: April 17, 2015, 09:50:23 am
content: I am thinking of building an arduino system for my aquarium.Amongst the most deadly hazards is ammonia and nitrites. Are there sensors to monitor these values electronically?

author: Unknown
author_rank: Unknown
timestamp: April 17, 2015, 10:31:25 am
content: Quote from: akis on April 17, 2015, 09:50:23 amI've looked into this a few times over the years. The simple answer is yes, but you won't like the price. Especially when you find out you'll be up for replacing electrodes every 18 months / 2 years in a freshwater tank, or every couple of months in a saltwater tank.(Ammonia & nitrate sensors are supposedly cheaper, but if you think about the nitrogen cycle you'll realise that testing those 2 alone is fairly pointless. You need to test nitrite...)For an electronics-based solution, the best bet I can see would be a colorimeter for use with the normal testing solutions, which you may be able to do with a camera or other colour sensor. But as a one-time fishkeeper, my advice is to develop a feel for the tank & how its nitrogen cycle runs. That means not rushing the setup, not rushing the stocking, not over feeding, regular water changes, and, most importantly - once it's stable, don't f&*k with the routine.Once you've got your tank running properly, you really only need to test once every few months (or if you notice something odd).

author: akis
author_rank: Frequent Contributor
timestamp: April 17, 2015, 04:38:31 pm
content: I am reading herehttp://www.timberlineinstruments.com/ammonia-analyzer/about ammonia analysers - it seems it is not simple it probably needs catalysts and various chemical reactions - not as simple as a refractometer test or a temperature sensor.

author: picandmix
author_rank: Frequent Contributor
timestamp: April 17, 2015, 10:02:12 pm
content: As the others have said, measuring those parameters is possible though expensive.Agree that they are very important in the early days of a new tank but once established in a well run tank its very unlikely either will be such a problem as to warrant such expensive sensors.Think other parameters are probably more important , like temp stability etc.The Seneye system seems to monitor Nitrates etc , though from users reports I'm not convinced by it.What are you concerns over monitoring them, are you doing something special in your tank / s ?If you are doing marines you will find a lot of info and Arduino based projects on Reef Central.com, though anything much more than a simple temp and light contrlller will mean moving to an Arduino Mega 2560 board for the extra i/o and memory neededHobby Components UK do their own Mega clone at a good price, got one myself.http://hobbycomponents.com/boards/557-hobby-components-arduino-compatible-r3-mega

author: akis
author_rank: Frequent Contributor
timestamp: April 18, 2015, 08:14:26 am
content: I forgot to switch on electrics for a day and a half and my established aquarium of 48 USg became toxic with ammonia. After a day or two of fish dieing I fololishly cleaned the filter trying to rid the disease (velvet, white spot) and inadvertently wiped out all bacteria. Now I am struggling with twice daily water changes and ammonia levels of 1mg/L when in the past it was 0. The disease/stress/toxins has killed a few fish, 5 so far.I was thinking there should be an "aquarium management" system that would (a) monitor and alarm and (b) control the parameters. An arduino with a GSM module would be able to send SMS texts with frequent updates for example. Or a web page to provide more info and control.But ammonia and nitrogen compounds in general are hard to measure and they are the most lethal. Of course we can measure temp, water pump operation, water levels, lights.

author: picandmix
author_rank: Frequent Contributor
timestamp: April 18, 2015, 09:04:25 am
content: Quote from: akis on April 18, 2015, 08:14:26 amWell it sounds like you have a lot of fish in there ( tropicals ?) and if you are still getting a lot of ammonia then you may have some dead fish still hidden in there ? would also suggest you get an in tank Ammonia remover from your lfs, there are types for either fresh or salt water use.Something to help renew the bacteria into the tank might also help along with the continued water changes.Assume you are dechlorinating treating / filtering the tap water ?As for management systems, yes there are lots around, the ready made Apex system is considered the current leader though you are looking at £500 Plus. - mind it does almost everything, pc connectivity etc.You can find plans for your own controller, I built my own a long thing ago, and it has an alarm so if the temp drops it will sound.However I have two projects almost completed, one is a battery backed up SMS device which the pictures show, so alerting you when away.Also doing a simple sounder temperature alarm for someone who like you forgot to turn on his main pump after cleaning and also nearly lost his tank.Both Ardunio based

author: akis
author_rank: Frequent Contributor
timestamp: April 18, 2015, 10:34:03 am
content: Excellent! Well done.Regarding my aquarium I did not have tap water treatment and was forced to make emergency water changes one night. For planned water changes I use the RO water because of the very slow production rate (about 6lt/hour) the RO cannot be used in an emergency. I have now bought 25lt jerry cans to store it in just in case.I have used a bacteria primer with those large water changes (API quick start) but I have read it's no good for long term stability. I think it will be better to maintain twice water changes until the filter and the plants pick up and start to eat on the ammonia.I make my own PCBs into which I incorporate an Arduino Pro Mini or an Arduino Nano or even a raw ATmega328P (although the Pro Mini is much better with 16MHz clock and voltage regulator). That way I can include a range of peripherals and sensors like a display, buzzers, op-amps for detection of differential voltages, current sense resistors, oscillators, pass FETs or relays to control power supplies and anything else really.What I am lacking is the ammonia/nitrites sensors, nothing as easy as a NTC thermistor !

author: picandmix
author_rank: Frequent Contributor
timestamp: April 18, 2015, 11:06:02 am
content: Think you are really looking to test after the horse has bolted.For the Ammonia to form due to a hardware fault, you need to loose total power, power to your main circ pump and /or heater/temp so I would have thought its easy enough to monitor those and get an early warning rather than wait for the Ammonia to form.I'm no chemist, but you can buy Redox probes for a reasonable price, would not one of those give you a warning reading if the tank was failing / ammonia rising ?Similarly would not the PH be noticabley affected as well ?

author: akis
author_rank: Frequent Contributor
timestamp: April 19, 2015, 12:38:55 pm
content: I do not know the correlation between ammonia/nitrites and pH.I think a monitoring system would be a great addition to any tank being you cannot take it with you when you go on holidays and you cannot just give it to someone else or find a good keeper.