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I started fishless cycling yesterday.  350 gallons.  The PH was around 8.5 so I added about an ounce of Muriatic acid.  A couple of hours later I checked and it had dropped to 8.2 or so.  Added another ounce.  This went on  every couple of hours until I went to bed and the last reading was 7.62.  This morning it hadn't changed much so I added another ounce.  later this afternoon I checked and it was 3.83 !  I just now checked and it had gone up to 4.33.

It took roughly 6 ounces of ammonia in order to get the level up to 3ppm. 

I also added a quart of Maxigrow when I started yesterday.

Should I freak out about the low PH or should I just wait and see what happens in the next day or so?

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Lock the chemical cupboard.... bind one hand behind your back with gaffa tape.... and use the other hand to write a thousand times...

 

"I will learn to be patient... and not fiddle with my aquaponics system...unless I know what I'm doing"...

 

Retest the pH in the morning and report back...

Exactly! Test every five minutes if you like, but adjust only a little every day or two, better yet, every week or two.

My hand is aching from writing all night. 

ThePH is now 6.17

I thought I was being patient.  I was told to check everything every hour or so which is what I did.  I have an 1800gph pump and my two GB are both cycling at least four times per hour so I know the water is getting good and circulated.

I've asked a few times what is "a small amount".  I asked "is it a few drops, a teaspoon, a tablespoon, 1/2 cup, etc".  I was always told "it just depends on your system size, blah blah blah".

I was just thinking about it and I can compare Aquaponics with cooking.  I'm an accomplished cook, taught in a cooking school, was offered a cooking show, to me it's just like breathing.  People will ask me "how much salt (or garlic, pepper, whatever) do I add" and I'll say "just a little, it depends on how big your pot is, what the other ingredients are,etc."  They'll always come back and say "but a teaspoon, a tablespoon, a cup, how much is a little"...

To me it's just so simple...."you know, just a little bit".  It's just second nature and I know exactly what it needs.

 

It's the same for you and the other pros.  Aquaponics has become second nature to you and you know instinctively what it needs.

I'm learning and I promise to be more patient.  But, how long should I have waited before adding more?

My ammonia is still where it was last night.  Between 2 & 3 ppm...No nitrites in sight.  I think they decided they didn't want an acid bath....

 

Thanks for your help.  I really appreciate it...

 

The reason it's tough to give a "recipe" for acid dosage is that not all water is created equal. If you are starting with distilled water, for instance, there is nothing in the water to counteract (buffer) any added acid (or base). Apparently, distilled water will absorb CO2 from the air, making carbonic acid (very weak, but still an acid) and immediately give an acidic reading. To say that a given sample of water is neutral, having a pH of 7.0, does not mean it has no base or acid. It means that the quantity of base components equals the acid components. If you begin with hard water, having a surplus of base components, it will take a good deal of acid to bring it down, and time for the chemistry to work. Whoever told you to test and adjust every hour is not clear on their chemistry.

If you start with high pH water, adding acid will give you an immediate acidic reading, but it will rebound back up to a slightly lower reading than the initial reading in a day. Add a bit more, same thing will happen. When the pH begins to show more of a net difference the following day, then lessen the amount you add to avoid overdoing it. Got it? So, approximately how much acid do you add? Well, I recently started a new tank, and it took two gallons of 14.6% HCL into 2200 gallons of water, at about a quart per day for a week to bring my 8.6 well water to 6.6. That was recklessly fast for a new, uncycled system containing fish, which is reckless practice to begin with. But hey, I'm reckless, and my appointment book is bigger than my calendar.

Ammonia, on the other hand can be estimated.

Also Bobby, giving people at least a hint of what you are working with helps. Is your HCL 3% or 30% strength? What is the KH reading of your water etc...but really...

Jon is right on the money though...your particular water parameters will determine "how much acid to add". No one but you will be able to answer that exactly in any precise or meaningful way (for your set and setting). You could easily take a 5 gallon bucket (or any known quantity of water) and add your acid in a measured and controlled way, making sure to take good notes, then extrapolate (multiply) a meaningful number from there.

This process with the 5 gallon bucket should take you a couple days because of the pH "bounce back" phenomena that Jon described. (unless you over do it and have to start all over with a new 5 gallons). 

But IMO, you will only hinder the ability of your bacteria to become establish ed by dropping your pH at or below 7 at this point in the game. Don't put the cart before the horse so to say. They really need some of that carbonate alkalinity in order to 'be fruitful and multiply'...

I'd listen to Rupert and lay off the acid...in fact I'd add more 'hard high pH' water back into the system to create a more hospitable environment for the bacteria. A pH of 6.1 pretty much seems to sucks ass for an initial start-up to cycling....

The PH is now 6.56

KH reading - I don't have a clue.  It's well water from my father's place.

The HCL is 31.45%

Stalite media.  Rinsed 5 times, soaked overnight in acid solution (1 cup HCL / 30 gallons of water) then rinsed twice more.

Sorry for jumping the gun on adjusting the PH.  I thought we were supposed to have it adjusted prior to cycling.

Hopefully it will be up close to 7 tomorrow.  I'll be much happier.  So, I'll leave it alone until it does what?  I will ask before I add anything!

I realize it's impossible to give an exact "recipe" but some sort of ballpark range would be helpful i.e. "per 1000 liters of water you may have to add between ?? and ?? ml daily."   I had to add 175ml (6oz) of Ammonia to get my initial reading to 2-4ppm.  I'd add an oz. then wait an hour or two.  It took about 9 or 10 hours.

 

When adjusting PH either up or down (which I won't do again without asking) we're supposed to do it gradually.  Should I have done it 5ml at a time and then wait a day?  That could take weeks, no?

Again, thanks for the help...Oh yeah, I've put the jug of acid up and out of sight....

 

I think an ounce of 31% for 350 gallons per day is fine, just give a day or two to determine where it lands. Weeks? Yes, it should take weeks, and it takes weeks to culture the nitrogen cycle anyway, so no time is wasted. And I agree with Vlad, if it doesn't rise above 7 by tomorrow, add some well water to get it above 7 (don't bother with pH up or potassium bicarbonate or anything, well water will work fine, IMO). Actually your original 8.5 is dandy for building bacteria, and adjust pH later (slowly). Keep you acid locked until cycled, fish planted, and fish stocked. The nitrogen cycle will acidify as well, hopefully enough to counteract your top-up water. By experimenting with a 5 gallon like Vlad said, you should get an idea of amount of acid you can expect to use. And don't get too complacent with that quantity, as your well water is likely to fluctuate with the seasons. My well water pH is near 7 in the spring, and near 9 in the fall (now).

Oh, and one more thing...it appears you are using a pH pen, which is fine, but you should check the results once per week with a litmus strip or reagent kit. I use my pen every day, but it does sometimes differ from cross checks, and needs to be recalibrated now and then.

Ok Bobby.. that's about what I thought it would rebound to...

 

By explanation.. the well water from your fathers place is highly "carbonate buffered"... and I suspect that the kH reading could well be 450+....

But I suspect it's probably also a high "general hardness"... gH.... a reflection of the mineral content... usually Calcium, Magnesium, Iron...

 

Both reflected in your initial pH reading of 8.5 ...

 

Adding the acid consumes some of the "carbonate buffer".... hence an initial pH drop.... but doesn't necessarily consume all of it... hence the pH rebound... and the reason why you've continued to add more acid.... and having stopped... the rise to 6.6...

 

Have you done any great harm in doing so... No... as you're fishless cycling... but Yes... as the level(s) below 6.0... would potentially be crashing your nitrifying bacteria...

 

As Vlad suggested... it would probably be best to "top up" the system... with a small (measured) amount of the well water... such that the pH is back around 7.0 -7.2...

 

Say a 10 gallon bucket.... and raise... and record the pH rise... (for further reference)....

 

This will bring the nitrifying bacteria back into a more optimal range...

 

As to how much acid should be used... well if the concentration is known.. it can be determined quite precisely.. by molar maths... (Vlad could help)... within a starting pH, tank volume.. and desired pH...

But, again.. as you're fishless cycling .. it doesn't really matter...

 

I'd just suggest though.. that you take a more "softly, softly" approach... smaller amounts, wait, test, observe...

 

If cycling with fish,or adjusting pH when you have fish... this approach is paramount.. as moving the pH (which is logarythmic) by more than 0.2-0.4 points ... is detremental, and potentially fatal to fish...

 

(Remember, that due to nature of the pH scale... a change of 1 point in pH... say 8.0-7.0.... is a 100% change)

 

There is a distinct relationship between ammonia toxicity, pH and temperature... that you need to research, and be aware of... if adjusting pH... when you have fish...

 

To adjust pH when cycling with fish... or when you have fish... 10 ml, 1/3 of an once.. is all that should be used at any one time... (to move pH between 0.2-0.4 points)... in a 1000L... about 300gallon...

There will come a time Bobby... when your system needs to be "buffered" back upwards.. due to the acidification due to the nitrification...

Your well water will then be beneficial... both as it will raise the "carbonate" buffering... hence pH... but also as the mineral content will benefit your plants...

Remember though... that by then.. you'll no doubt have fish... and not want to move the pH too quickly...

So remember... the 10 gallon bucket top up suggestion... and recording the pH change... it will give you a guide for later...


 
Bobby McGovern said:

The PH is now 6.56

KH reading - I don't have a clue.  It's well water from my father's place.

The HCL is 31.45%

Stalite media.  Rinsed 5 times, soaked overnight in acid solution (1 cup HCL / 30 gallons of water) then rinsed twice more.

Sorry for jumping the gun on adjusting the PH.  I thought we were supposed to have it adjusted prior to cycling.

Hopefully it will be up close to 7 tomorrow.  I'll be much happier.  So, I'll leave it alone until it does what?  I will ask before I add anything!

I realize it's impossible to give an exact "recipe" but some sort of ballpark range would be helpful i.e. "per 1000 liters of water you may have to add between ?? and ?? ml daily."   I had to add 175ml (6oz) of Ammonia to get my initial reading to 2-4ppm.  I'd add an oz. then wait an hour or two.  It took about 9 or 10 hours.

 

When adjusting PH either up or down (which I won't do again without asking) we're supposed to do it gradually.  Should I have done it 5ml at a time and then wait a day?  That could take weeks, no?

Again, thanks for the help...Oh yeah, I've put the jug of acid up and out of sight....

 

Hi guys,

 

I'm using the HM Digital PH-200 Waterproof pH and Temperature Meter.  When I got that heart stopping low reading the other day I checked the calibration and it was spot on.

 

Today the PH is 7.2

I'm a very happy camper right now...

 

I have a nearly full IBC of my father's well water to use for top ups...The acid is put up.  I think I'm ok now!

I'll keep you posted as to what the PH does.....

 

 

 


 
Jon Parr said:

I think an ounce of 31% for 350 gallons per day is fine, just give a day or two to determine where it lands. Weeks? Yes, it should take weeks, and it takes weeks to culture the nitrogen cycle anyway, so no time is wasted. And I agree with Vlad, if it doesn't rise above 7 by tomorrow, add some well water to get it above 7 (don't bother with pH up or potassium bicarbonate or anything, well water will work fine, IMO). Actually your original 8.5 is dandy for building bacteria, and adjust pH later (slowly). Keep you acid locked until cycled, fish planted, and fish stocked. The nitrogen cycle will acidify as well, hopefully enough to counteract your top-up water. By experimenting with a 5 gallon like Vlad said, you should get an idea of amount of acid you can expect to use. And don't get too complacent with that quantity, as your well water is likely to fluctuate with the seasons. My well water pH is near 7 in the spring, and near 9 in the fall (now).

Oh, and one more thing...it appears you are using a pH pen, which is fine, but you should check the results once per week with a litmus strip or reagent kit. I use my pen every day, but it does sometimes differ from cross checks, and needs to be recalibrated now and then.
Sounds good. Just for giggles, check you pen against a litmus strip. Cheap and easy to gain peace of mind. I've had a pen test 7 and 4 exactly for their respective calibrating solutions, yet vary from litmus and reagent substantially when measuring AP water. I don't know which is more accurate, but the litmus always agrees with the reagents, so I put my faith there

I just tested the water using the pH200=7.18, the API was 7.6 and the test strip (for the pool) was 6.2-6.8.

With all the drama with my pH my arugula and lettuce have sprouted in just 36 hours!  Actually a root in 18 hours and the cotyledon in less than 36.  I filled a pump sprayer with the Maxicrop FT water and I mist the top of the media a few times a day.  The parsley and cilantro haven't done a thing yet.  I've never seen anything like that in soil.  I'm flabbergasted!

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Hi Bobby.  Parsley and cilantro are both not only poor germinators, but they also take a long time to germinate - probably at least a couple weeks, in my experience...especially when compared to lettuce, which is the Speedy Gonzalez of the seed sprouting world.  

You are getting great advice here on handling your pH, BTW. 

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