Aquaponic Gardening

A Community and Forum For Aquaponic Gardeners

Hi all, I'm brand new to AP and built a little micro system with a 20 gallon tank, some feeder gold fish and basic garden herbs to get my hands dirty so to speak before attempting a real system. I lost a couple of fish last night to an ammonia spike. I had been using a liquid test for ph that I wasn't real happy with as its hard to tell the exact color gradient, not to mention the levels go in increments of .5. So I bought an electronic tester for comparison (2 days to late I'm afraid). My question is I've read to bring down ph at this and other sources

to not use citric acid. But in the same sentences they recommend using General Hydro's buffer which I have. But on the back of the ph down bottle it clearly says "Contains phosphoric acid, Citric Acid and mono ammonium phosphate." Any help in deciphering this contradiction would be most helpful.


Views: 684

Reply to This

Replies to This Discussion

Lowering your pH while cycling is absolutely counterproductive IMO. Your main concern at the beginning is cycling up your bio-filter. Meaning getting your microbes to initiate and complete colonization of all surfaces in your system. A pH of 8 to 8.5 is ideal for this. That same pH is also wonderful for the fish. Unless you have liquid rock for water there should be no need to mess with your pH at this point. Besides the nitrification process will acidify your water all on it's own (that is, if you give it a chance to get going).

Citric acid is great for killing off or inhibiting your bio-filter. IMO... Plain old HCL gets my vote for 'best' choice for a number of reasons. (AFTER YOU ARE ALL DONE CYCLING AND STILL FEEL YOU NEED TO LOWER pH...Though realistically, unless you have a buffering media like limestone gravel, or super hard top-up water, in the future you will more than likely be needing to RAISE your pH every once in a while and not lower it).

No contradiction, that pH Down product will do what is says just fine, BUT it seems to be made for use in a sterile hydroponic environment where you don't have a biofilter (bacteria) to worry about.

I'm not saying it will kill off an established bio-filter necessarily, but it certainly wouldn't help an establishing one...I wouldn't use it, especially since there seem to be much better choices out there... (That product doesn't seem like the best of pH Down choices for an AP store to sell, especially when you consider that HCL will, in addition to lowering your pH, will bind Iron(III) into Iron (II)  and the Chloride released could only help your fish tolerate Nitrite spikes better...which is why people add salt (NaCl), for the Chloride)...

But again, I wouldn't bother lower my pH while cycling with anything. It'll just slow cycling down and stress out the probably already stressed fish.

What is the pH of your system water pH anyways?

The reason for no citric acid is because it is an anti bacterial and will kill the good bacterias.

Phosphoric and phosphate acids provide additional benefits as far as nutrients for the plants.

Vinegar can be used but it might take a lot.

I have heard of lots of people using PH down a lot just make sure its not the aquarium kind. If its not I am assuming there must be a very small amount of the citric acids. Just might be better to find something else for later.

Of course you shouldn't use anything at all normally anyways...

"they recommend using General Hydro's buffer which I have. But on the back of the ph down bottle it clearly says "Contains phosphoric acid, Citric Acid and mono ammonium phosphate."


I wouldn't use any of them.. even after cycling... and as Vlad says.. never during...


Adding "phosphates" ... phosphoric acid... or ammoinium phosphate.... will just undoiubtably cause an algael bloom... and swing your pH up really high... totally counterproductive....


And same after cycling... but with the added disadvantage of also adding "ammonium" to a cycled system.. probably stocked with fish...


That's the trouble with books, and e-books written by people who have little realtime knowledge of aquaponics before they write them... and jsut cut and paste other peoples stuff off the net...


Google is your friend... but it's also full of morons and disinformation...


Look to the established members... particularly those on the long term establishe forums...


I haven't seen a question posted here yet... that hasn't been discussed elsewhere... before, or since... this forum even started...

Wow, I wasn't expecting responses that quickly, thanks guys.

Vlad, the ph is 7.4. Water temp is 19.6c, Ammonia is in the 3 range. Nitrites are between .5 and 1. Nitrates are 15-20. I'm using hydroton and have 10 little various herbs planted with 5 remaining goldfish.

Rupert, you hit the nail on the head. I've been fascinated with AP since I first saw Wisconsin Will's video a year ago. Since then I've bought and read a half dozen books and watched countless vids from diy backyard "experts" to Nelson, Pade and Hellam's. But as you said the more you read and see the more diluted and across the board the answers become, which is why I figured I'd start with a little tiny system.

I'm in the process of selling my house to move out onto some acreage and will have some funds to play with for the real deal and will probably start a different thread for your opinions on the pretty radical plans I'm looking at implementing.

Thanks again for any and info/opinions.

Good Deal Pat, Looks like you already got the good advice.

good Luck with the move.  Just in time I expect since by the time you get your little micro system cycled up you will be chomping at the bit to start a bigger system. Warming, Aquaponics is addictive.

Your pH seems fine Patrick. Most pH related deficiencies (Iron it seems mostly, ...and you'll probably see that first in your Oregano if you have any) your plants may experience, can be dealt with using chelated Iron. For most anything else that may crop up (unlikely with just some herbs) while your cycling, you can foliar feed if you need to.

Getting the temps up a bit could help speed things up on the bacteria side if you have a convenient/cheap way to do it.

I guess I'd just that you don't overfeed your fish...You don't really need a higher ammonia level than what you have (maybe a bit lower even since you have the fish already in there)?...adding some NaCl at a rate of 1 to 2ppt might help them make it through the Nitrite spike, if they haven't gone through that already. I know that TC has some good blogs on that topic should you need the info.

Well, at least you took the time to read those books and watch those vids. I'm sure I tend to 'over think' things at times, but I'm sometimes flabbergasted when people throw a system together seemingly after watching just a 30 second youtube video as their only source of info, don't know that they even need to test for anything...let alone interpret or know what those test results mean...then wonder why everything died...amazing.  

Some of the best sources of information that I've come across for helping me wrap my mind around aquaponics, have had NOTHING to do with AP itself. There are tons of studies on your bacteria in the waste water treatment realm...Plant biology from the hydroponics research sphere (plants I do have a bit of experience with) and RAS on the fish end of things...Granted you need to assimilate all that info in a way applicable to AP (and your specific 'version' of it), but if you plan on going bigger, especially "small commercial" or even "hobby farm", I'd suggest doing the legwork in those three fields (if for nothing else than to avoid the AP e-book bandwagoneer types of crap info that Rupert mentioned) in addition to what Rupert already suggested.

And as with any addiction...expect it to cost you more and more...and more than you'd think

I just read that article you linked and I take it back when I said "no contridiction there..." My apologies Patrick. The information written there certainly is contradictory when considering the ingredients of that product.

Also, in the very same sentence the author says ..."...Raise pH either by using “pH Up” or by alternating alternatively use calcium hydroxide – also known as “hydrated lime” or “builder’s lime” with potassium carbonate (or bicarbonate) or potassium hydroxide (“pearlash” or “potash”)...."

Potassium hydroxide IS NOT known as "pearl ash" or "potash" it is also known as "lye" (keep in mind though that there are two kinds of lye, one is potassium hydroxide, the other is sodium hydroxide).

Pearl ash or potash is Potasium Carbonate...

There's other stuff in there right below in the next section where the Author states that:

"...How might salt (sodium chloride) help? Sodium Chloride helps mitigate nitrites because the chloride ions bind with the nitrites and thereby help keep some of the nitrite out of your fish..."

That's really not true. I don't think there is any "bonding" going on between any Chloride and any Nitrite (nor could there ever least not in this Universe scenario... seeing as how they are both negatively charged and all.)

Best as humans can tell, Chloride seems to mitigate Nitrite toxicity through a mechanism called "competitive inhibition".

There are some other things in there too which some may find 'contradictory' (though Rupert may call it by another name I suspect)...

I don't mean any disrespect towards the Author, just pointing out some of the things some people would have contention with. 

Something else I've not been real sure of is is an exact formula for how much liquid nutrients (maxicrop) and chelated iron I should add to 20 gallons of water to be beneficial to the plants. All the herbs look good so far but haven't been growing very fast. I've only added a cap full of each to a gallon of water once 1 week into it. I started another thread on the next houses greenhouse plans I'd love for you to look at and give your thoughts on.


in a 20 gallon system, a pinch or spoon full or cap full every couple weeks till the system is cycled up is probably plenty.  Then after the system is cycled up, just wait till the plants show signs that they need it.

Good to know.
Ive got a little update. After 2 weeks I've got decent plant growth (I think), but my levels are fluctuating. I added pics to my profile, I'm unable to link in post, either a linux or browser security thing. I added 5 little red worms to the clay I don't no if its coincidence but my ph is down to 6.3, ammonia is around 4 now, nitrites are around 1-1.5 and it seems nitrates are decreasing (maybe the 2 decent sized peppers I threw in to fill up last lots). I lost 3 of the 7 goldfish last week (brown blood I guess) and added 6 more slightly larger ones for a total of 10 now. According to this chart I shouldn't have to worry about the ammonia levels at my temp (24c) and ph level.

If it is an accurate chart/source. And it doesn't go into detail about the nitrite levels. Do they alternate like ammonia on a sliding scale. Should I be taking steps now or let nature run its course for a little while?

Don't do anythnig... let nature run it's course...


And don't feed your fish.... your ammonia is still very high... as are your nitrites.... make sure you're salted to 1ppt...


You're still uncycled...

Reply to Discussion


© 2020   Created by Sylvia Bernstein.   Powered by

Badges  |  Report an Issue  |  Terms of Service