Fishless Cycle

[TedsReef]

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[Calpoly2103]

For the book nitrite is NO2 and nitrate is NO3.



It is easy to explain. All hobby nitrate tests I know about is based om the method that first reduce NO3 to NO2 and after that analyse the NO2 level. Your colour chart will after this translate the read NO2 into the orginal NO3 value. If you have NO2 already in the water (before the nitrate had been reduced to NO2) the NO3 test will give a false result. Your test show 40 ppm NO3 but its false - you probably have 0. But your NO2 level of 1 ppm will cause the NO3 test to show between 50 - 100 time more than the orginal value. IMO - it is total worthless to analyse NO3 before the tank is full cycled and there is no NO2 in the water.

Sincerely Lasse

Hi Lasse,

You gave me excellent advice before, so i was hoping you could help me answer this question. I've done a bunch of reading, but as usual it leads me to various opinions. My tank is still in the cycling process, day 13. I hooked up an apex last night, and PH seems to be steady at 7.8. Is there a reason PH is so low? I'm using Red Sea Coral Pro salt. Shouldn't it be around 8.0-8.4? Ammonia levels are 0, Nitrite 0.25, Nitrate 10.
Tank temperature 78.5....
Also, my ORP is at 185, and this confuses me a lot. Honestly i just wanted to use ORP to gauge if something has died or just general changes in water parameter.

Thanks for any advice you may have.

 

[ReefGeezer]

Hmmm so I am absolutely in no rush whatsoever. I am however still confused if I should just use ammonia alone or ammonia and some type of bacteria like dr Tim’s...

Ammonia alone is fine. Not too high though, maybe 3 ppm. The bacteria that are needed to perform the cycle are already present in small numbers and will multiply as the nitrogen compound (ammonia, nitrite, and nitrate) levels increase during the cycle.

Also if you system is completely void of organics... like brand new and started with dry sand and rock... adding a few pellets, a small chunk of raw shrimp, or a little flake food will help the process. You only need a little or either though. This will add just a little carbon and phosphate that are needed in the process.

 

[Lasse]

I ´m not familiarly with APEX and how their measurements work. therefore, I will only give general advices.

First pH. Have you calibrated it since the move? You need to do that. Clean the small glass bulb and the areas around it with a smooth toothbrush. Rinse it in water (best – RODI water) Calibrate. Let is run for a couple of days – do you have daily variation of the pH?

Next question is – do you have a skimmer?

Do you live in areas there you need a rather airtight house? How many people are you in the household – especially in the areas around the aquarium?

These questions are because what´s affect your pH most is the carbon dioxide level around your aquarium – especially if you have an effective skimmer. Having a reef tank and measure the pH make you to understand the word “ocean acidification”.

But calibrate first – after that we can deal with the pH if it still show low levels.


The same with the redox probe – calibrate. But there is a certain thing with ORP measurements. It will take up to 5 days before a new probe (in your aquarium) will give stable readings. 180 is no catastrophe but after 5 days you probably will read a little bit more. If you ask around – 360 mV seems to be an accepted value. But IMO – the best value for your own tank is relative and can be all from 200 to 400 mV. Just measure and look at your livestock. ORP measurement can be done but to figure out what they mean – that´s another question


Sincerely Lasse

 

[Calpoly2103]

I ´m not familiarly with APEX and how their measurements work. therefore, I will only give general advices.

First pH. Have you calibrated it since the move? You need to do that. Clean the small glass bulb and the areas around it with a smooth toothbrush. Rinse it in water (best – RODI water) Calibrate. Let is run for a couple of days – do you have daily variation of the pH?

Next question is – do you have a skimmer?

Do you live in areas there you need a rather airtight house? How many people are you in the household – especially in the areas around the aquarium?

These questions are because what´s affect your pH most is the carbon dioxide level around your aquarium – especially if you have an effective skimmer. Having a reef tank and measure the pH make you to understand the word “ocean acidification”.

But calibrate first – after that we can deal with the pH if it still show low levels.


The same with the redox probe – calibrate. But there is a certain thing with ORP measurements. It will take up to 5 days before a new probe (in your aquarium) will give stable readings. 180 is no catastrophe but after 5 days you probably will read a little bit more. If you ask around – 360 mV seems to be an accepted value. But IMO – the best value for your own tank is relative and can be all from 200 to 400 mV. Just measure and look at your livestock. ORP measurement can be done but to figure out what they mean – that´s another question


Sincerely Lasse

This is a brand new tank currently cycling (day 13). Also it's a brand new PH & ORP probe so they were never moved. I put them both in last night. PH probe is calibrated and is accurately showing 7 PH and 10PH using the calibration solutions.

The tank is in the corner of my living room. The dogs are home all day but usually not near the tank. My wife and I are the only people who live there.

Right now, I don't have anything in the tank except sand, live rock, return pump, a few mp10's. I will have a skimmer but its on its way. Also have a light but not on yet.

 

[Dkeller_nc]

You don't note what your alkalinity is. When you cycle a system, you're usually adding either inorganic ammonia, or an organic source of nutrients such as fish food, shrimp from the supermarket, etc... The conversion of ammonia to nitrate consumes alkalinity; at some point, you may have established enough nitrate-reducing bacteria that you recover some of this alkalinity from the reduction of nitrate to nitrogen gas, but in a new tank, there's a fair bet that you've only gotten the first half of the cycle going, so it's possible your alkalinity is quite low. That will produce a somewhat lower pH, as will an over-abundance of carbon dioxide inside a well-sealed home, as Lasse noted.

 

[MnFish1]

You don't note what your alkalinity is. When you cycle a system, you're usually adding either inorganic ammonia, or an organic source of nutrients such as fish food, shrimp from the supermarket, etc... The conversion of ammonia to nitrate consumes alkalinity; at some point, you may have established enough nitrate-reducing bacteria that you recover some of this alkalinity from the reduction of nitrate to nitrogen gas, but in a new tank, there's a fair bet that you've only gotten the first half of the cycle going, so it's possible your alkalinity is quite low. That will produce a somewhat lower pH, as will an over-abundance of carbon dioxide inside a well-sealed home, as Lasse noted.

This is true - however, I was under the impression that alkalinity helps 'balance' pH - but long term (i.e. hours) doesnt change pH. Also as nitrate is turned to N2 - that is returned - am I correct?

 

[Calpoly2103]

Well, I measured my ALK at the beginning of the cycle 13 days ago, and it was pretty high at 12 (Using red sea coral pro). I will check my big 3 today and report back. Currently my tank is processing Ammonia into Nitrite fairly quickly, and takes about two days to process nitrite to 0 from 2ppm.

 

[Dkeller_nc]

This is true - however, I was under the impression that alkalinity helps 'balance' pH - but long term (i.e. hours) doesnt change pH. Also as nitrate is turned to N2 - that is returned - am I correct?

Honestly I'll have to think through that first point; from what I remember about carbonic acid/bicarbonate/carbonate equilibrium, it was essentially impossible to have a pH below about 7.8 under normal atmospheric (i.e., CO2 ~ 400 ppm) conditions with an alkalinity of seawater. However, I'm not entirely sure about that now that you bring it up.

Yes, the carbonate consumption of the ammonia>nitrite>nitrate oxidation reaction is returned when nitrate is reduced by bacteria to nitrogen gas. The catch is that often in our reef tanks the bacteria required to efficiently reduce nitrate to nitrogen aren't present in sufficient numbers, and tanks accumulate nitrate unless it's removed by some other means. So in that scenario, one would expect the alkalinity to go down commensurate with the amount of ammonia (or organic waste) converted to nitrate.

 

[Lasse]

Honestly I'll have to think through that first point; from what I remember about carbonic acid/bicarbonate/carbonate equilibrium, it was essentially impossible to have a pH below about 7.8 under normal atmospheric (i.e., CO2 ~ 400 ppm) conditions with an alkalinity of seawater. However, I'm not entirely sure about that now that you bring it up.

Yes, the carbonate consumption of the ammonia>nitrite>nitrate oxidation reaction is returned when nitrate is reduced by bacteria to nitrogen gas. The catch is that often in our reef tanks the bacteria required to efficiently reduce nitrate to nitrogen aren't present in sufficient numbers, and tanks accumulate nitrate unless it's removed by some other means. So in that scenario, one would expect the alkalinity to go down commensurate with the amount of ammonia (or organic waste) converted to nitrate.

You are basically right if we talk about freshwater with an alkalinity around 3 in KH. But in saltwater with KH > 6 - the amount of carbon dioxide in the air is the most important factor. I measure the CO2 level in my household - normally 2 persons. During wintertime (well isolated apartment) we often read above 800 ppm in the living room when we are at home and I can see on my pH when my grandchildren visit us. And if they stay over - I can see on my aquarium pH when they awake. Yes - 400 ppm will result in pH around 8.15 - 8.2 if it is a complete equilibrium. However it is seldom that. In this case – some CO2 can be produced in the aquarium faster than equilibrium occurs.

In this case - I would start the skimmer and see if the pH will change. And after two weeks – recalibrate the pH probe. My experiences say that brand new pH probes need an acclimation period. I think that the ORP will change in a couple of days and especially if you start the skimmer. Comeback with the result – this is an ongoing investigation

Sincerely Lasse

 

[Dkeller_nc]

Lasse -

Ha! Well, you'll have to forgive me, scientist or otherwise, we're all influenced by our day to day experience. In my case, I live in a house built in 1940. I love old houses, but it isn't exactly airtight - the most CO2 I've ever measured indoors was about 450 ppm.

One rather irritating thing about the 'net is that if a particular subject is "in the news", it becomes difficult to find actual data as it gets drowned out by repeated articles on the same subject from different science-oriented popular science sites. In this case, I figured it would be relatively easy to look up a chart listing the pH of seawater versus an atmospheric carbon dioxide concentration in the range of 400 ppm - 1200 ppm. No such luck - all I could dig up this morning was endless articles on anthropogenic CO2 generation versus ocean acidification. Certainly important, but not all that helpful when we'd like to know what the pH would be for seawater in equilibrium with a range that we might expect for an example CO2 concentration, such as you listed (800 ppm).

Calpoly - Lasse's dead-on about the pH probe recalibration. In theory, a biofilm on the junction of a pH probe shouldn't make any difference to the measured pH, the probe would just take longer to settle at that pH. In practice, I've observed the same thing as Lasse - if I replace a probe, or if I clean one with 0.1N HCl, the probe will calibrate perfectly. But after a couple of weeks in the system, I find that the pH is significantly off of the true value, although recalibration does correct that offset.

 

[Calpoly2103]

Lasse -

Ha! Well, you'll have to forgive me, scientist or otherwise, we're all influenced by our day to day experience. In my case, I live in a house built in 1940. I love old houses, but it isn't exactly airtight - the most CO2 I've ever measured indoors was about 450 ppm.

One rather irritating thing about the 'net is that if a particular subject is "in the news", it becomes difficult to find actual data as it gets drowned out by repeated articles on the same subject from different science-oriented popular science sites. In this case, I figured it would be relatively easy to look up a chart listing the pH of seawater versus an atmospheric carbon dioxide concentration in the range of 400 ppm - 1200 ppm. No such luck - all I could dig up this morning was endless articles on anthropogenic CO2 generation versus ocean acidification. Certainly important, but not all that helpful when we'd like to know what the pH would be for seawater in equilibrium with a range that we might expect for an example CO2 concentration, such as you listed (800 ppm).

Calpoly - Lasse's dead-on about the pH probe recalibration. In theory, a biofilm on the junction of a pH probe shouldn't make any difference to the measured pH, the probe would just take longer to settle at that pH. In practice, I've observed the same thing as Lasse - if I replace a probe, or if I clean one with 0.1N HCl, the probe will calibrate perfectly. But after a couple of weeks in the system, I find that the pH is significantly off of the true value, although recalibration does correct that offset.

Just out of curiosity, how do you guys measure CO2 in your homes? I see there are some meters on amazon for around $100...

I'll probably be calibrating the probe every month or couple months while also testing via salifert kits. I have backups to double check against, or plan to at least

Speaking of calibrating. Do you guys all buy those Neptune calibration packets every time you need to re-calibrate?

 

[MnFish1]

Just out of curiosity, how do you guys measure CO2 in your homes? I see there are some meters on amazon for around $100...

I'll probably be calibrating the probe every month or couple months while also testing via salifert kits. I have backups to double check against, or plan to at least

Speaking of calibrating. Do you guys all buy those Neptune calibration packets every time you need to re-calibrate?

I don't - I just try to keep windows open - when. possible - otherwise I assume that when its -20 or 90 that the pH will be a little lower in the tank. During this time I try to run the fan in the bathroom near where the tank is - to promote air circulation (as the tank is in the basement)

 

[Calpoly2103]

I don't - I just try to keep windows open - when. possible - otherwise I assume that when its -20 or 90 that the pH will be a little lower in the tank. During this time I try to run the fan in the bathroom near where the tank is - to promote air circulation (as the tank is in the basement)

Hmm..i see. Perhaps I will schedule my nest to turn on several times a day for 15 minutes just to circulate the air in the house as well. Thanks for the suggestions.

 

[Kal93]

Hmmm so I am absolutely in no rush whatsoever. I am however still confused if I should just use ammonia alone or ammonia and some type of bacteria like dr Tim’s...

Use ammonia and Dr. Tim's (which is an excellent product BTW--my tank was cycled in 3 weeks). Dose ammonia daily depending on how many fish you want to add after cycling (~2 ppm per fish).

 

[MnFish1]

Hmm..i see. Perhaps I will schedule my nest to turn on several times a day for 15 minutes just to circulate the air in the house as well. Thanks for the suggestions.

Yes - I do that as well

 

[Lasse]

I use this - not scientific but rather good. Go here - Go to Sweden. Find Gothenburg at the westcoust. Zoom in so you can see the road E45. Follow that road 20 km north to Bohus - look at the right up in the hills - you see one station there - Its mine But you can only see my outdoor temperature.

Sincerely Lasse

 

[Lasse]

Dubble post

 

[Dkeller_nc]

Just out of curiosity, how do you guys measure CO2 in your homes? I see there are some meters on amazon for around $100...

I'll probably be calibrating the probe every month or couple months while also testing via salifert kits. I have backups to double check against, or plan to at least

Speaking of calibrating. Do you guys all buy those Neptune calibration packets every time you need to re-calibrate?

In my case, I use something like this that I borrow from work. I occasionally measure it just for the heck of it, but I think it'd be hard to justify for a casual reefer.

 

[Gogoggansgo]

There is a thread on here (@Dr. Reef) - that compares in a fairly scientific manner with multiple repeats that suggest that Fritz Turbo 900 can when dosed to the proper directions - lower ammonia from 8 ppm to 0 in 1.5 days. Some of the others need a carbon source - and then they also work.

I have never done a fishless cycle - I've added Bacteria (sometimes a bit more than the dose because im never sure exactly the tank volume - and added fish at the same time - with no problem. There is also the @Lasse method for starting a tank (which is close to mine) that is well described here.

Though I like the idea (seriously) that patience is valuable in this hobby - It always surprises me when someone says - I've had a tank in my living room for 3 months with just rock - I personally do not have that much patience. I tend to think that the more quickly you can cover the rock with 'living things' whether its coral or zoos or whatever, the more quickly you will not have diatoms, etc. IE the corals out compete the algae. But I have no complaint for those who do it another way - to each his own.

I’m on 2/1/2 weeks with my tanks and it’s currently more than half way through the cycle with fish. To be blunt after watching everything go up and down. Next time I’ll just add ammonia, i feel bad for the little guys. Right now I’m waiting for the nitrites to drop, my nitrates are rising which is good. Once my nitrites get too 0 and i do a water change the cycle is done. All in all I’d say 3-4 weeks if you watch everything. If ya threw the bacteria in and used live rock like i did and didn’t test. Ya probably never now the tank was going through it’s phases