New system, should I lower PH

Cylo

Hey guys, I have an IBC chop and flip setup with clay balls for media. Got 22 silver perch fingerlings in approx 600L of water with 6 strawberry plants & a capsicum which is less than 1ft high

PH 8
Ammonia 0.5
Nitrite 0
Nitrate 0
Temp 18.6

I started out with tap water which I cycled for 3 days to remove chlorine, then for 1 week today Ive had the fish and plants in

There was a small amount of water added from the fish in the bag they came but i didnt think to ask whether that was from the tank they were in, I would assume it was but maybe not. I do have a dam down the back im not sure whether thats suitable for adding to the system

I have some hydrochloric acid, should i use this to lower PH, have read on here that its best to remove some water and adjust its PH then add that back rather than adding acid straight into FT

Thanks very much!

Mr Damage

You are way overstocked, your system is uncycled, and it has a high water pH... a recipe for disaster... You are probs just days away from killing your fish, or lots of 30% water changes.

IMO you have 2 options:

(1). Temporarily relocate, or give/sell the fish to someone else, cycle the system without fish, then add the correct amount of fingerlings back in once cycling is complete, ie: 1x SP per 20L of wet gravel.

(2). Look in Google images for "Ammonia Toxicity Chart Ecofilms", find out at what point the Amm in your system is toxic, do partial (30%) water changes as required to keep the Amm below a toxic level while your system is cycling. You will need a water aging tank of at least 30% of your system water volume, aerate the water in it for at least 24hrs prior to use. In that time you can add some HCl acid to that water to reduce the pH a bit, but not too much, you don't want to shock the fish with a large pH difference when you do the water changes.

Cylo

Thank you kindly for your advice. The gentleman i purchased the fish from advised me that once the fingerlings grow then i would need to add another grow bed, it sounded correct as a fingerling wont produce the same waste as a larger fish, obviously theres more to it than this?

Yes according to the chart once 0.6 ammonia level will start to become toxic.

I could put 10 fish in the dam down the back I hope thats a safe option for them.

I have a 10000 litre concrete water tank here, if the ph of that is on then maybe i can use it to do 30% changes, it wont have chlorine is that the only reason for 24hr Aerating?

Cylo

PH of the concrete tank water is 8.2

That water is originally tap water thats been sitting un used for many yrs

Mr Damage

Yep, the 24hrs of aeration is primarily to remove chlorine, but also for adding acid if required and giving it time to do it's thing and have the pH stabilise.

Just as an example, if you were to get a drum of high carbonate water, with say a pH of 8.2, add a given amount of HCl acid, which initially dropped the pH to say 6.0 for examples sake, after 24hrs you'd most likely find the pH was back up to 8.2, or very close to it.

When you first add the acid and measure the pH shortly after, you are measuring the acid you just added, but then over the next few hours the acid will react with the carbonates in the water, reducing the carbonate level slightly, but dissipating as it does. After 24hrs there will be no acid left, but still plenty of carbonates, so the pH will have risen back up to, or nearly to where it was before you added the acid.

If you repeated this process a number of times, to the point where the pH stayed down in the low 6's, you'd know you've removed the overwhelming majority of the carbonates from the water.

While a pH of 6.0 is too low for doing 30% water changes, as it would alter the system water pH too much in one hit, if you used the same process and managed to drop and stabilise the pH in the water ageing tank to somewhere in the low 7's, when you do your 30% changes it would drop the system water pH a little each time, making any Ammonia in the system less toxic.

Cylo

Thanks for your further advice!

Would a bucket of water from the dam be an idea to help speed up the cycling time or possibly add stuff i dont want from there?

Mr Damage

Personally I wouldn't bother, or risk it. The fingerlings would've brought beneficial bacteria with them.

Cylo

sounds good, I should have taken some water from the aquaponics system the fish supplier has in his shop. If I had done that what would be an adequate amount for seeding a system 1 IBC tank 1 grow bed. I have searched but haven't been able to find this finer detail, maybe its a very small amount. This water that came with the fingerlings would have been from the plain fish tank rather than the aquaponics fish tank, probably has the same good bacteria but I'm assuming I needed a lot more than the couple of litres they came with

I have been able to access some rain water after 76 days of no rain in Sydney, so have used this to do a 30% water change, PH is much lower with the rain water so that should help lower slightly each day and lower ammonia level. Ill continue with this each day in attempt of getting the PH down to 6.5-7 so the ammonia can build to its required level for cycling

Mr Damage

Yep, the same required bacteria would be present in both the aquarium and his aquaponic system.

There is no adequate amount, seeding isn't required. The bacteria show up on their own and the colony starts growing the instant the water conditions are suitable, ie: The water is chlorine free, well aerated, and there is even the slightest amount of Ammonia. The fish themselves would've brought billions of them into the system, even without the water they came with.

I would avoid doing water changes just as a matter of course, only if the Ammonia is approaching a toxic level.

Don't be in a rush to drop the pH too far. If you do want to do extra water changes with the rain water in an attempt to reduce the pH a bit and therefore Ammonia toxicity, I would only aim for a pH in the low 7's. If you look on the Ammonia Toxicity Chart you'll see even at that level the Ammonia toxicity will be greatly reduced.

If you drop the pH below 7.0 there will be very little in the way of carbonates and in a few weeks your pH will take a dive and you'll be wishing you had carbonates in the system.

The "required level" of Ammonia for cycling is not much at all. I have cycled a system very successfully with a max Amm level of 0.5ppm. Increasing the Amm level won't speed up the cycling process.

ALL you need to worry about is watching your Amm doesn't approach a toxic level and then also watching out for the Nitrite spike and being prepared to act quickly when it happens. If the Nitrite reaches 1.0ppm add sea salt at 1gm per litre. If it reaches 2.0ppm then do daily partial water changes until it starts dropping on it's own.

Cylo

Sounds good thanks very much! Giving me confidence its running ok. Currently the ph is down to 7.5 and ammonia 1ppm. No nitrite showing up but there is 0.5 nitrates, at first i was pleased thinking its cycling already but then realised thats probably from the rain water.
Only feeding then a very light amount once per day, they dont come up to surface to pick at food they wait for it to sink and still very spooked

Cylo

Ive got ph 7.5
Ammonia 0.5ppm
Nitrite btwn 0.5ppm - 1.0ppm
Nitrate 5.0ppm

Nitrites have shown up, not definitively 1ppm yet maybe tomorrow Im unsure.

How important is it I add salt as you recommend is it ok to avoid that step or? Reason is ive been reading strawberries aren't so keen on salt & theyre 1st on my list of plants to do well

Thanks!

Mr Damage

Cylo wrote:

How important is it I add salt as you recommend is it ok to avoid that step or? Reason is ive been reading strawberries aren't so keen on salt & theyre 1st on my list of plants to do well

Fish are far less keen on Nitrites than Strawberries are about salt at 1gm per litre.

dlf_perth

> Fish are far less keen on Nitrites than Strawberries are about salt at 1gm per litre.

the other thing is that it is temporary. You just have to get through cycling which will only be a couples weeks at most till the nitrites disappear for good. Once nitrites are down you can always drop the salt by doing fairly modest water changes. The strawberry plants will go OK in that short time.

Cylo

Thanks guys, bought some pool salt today ready.

If nitrites stayed at 1ppm and dont spike higher for a week or so would this be acceptable with no salt or too stressful on the fish.

dlf_perth

oxygen & salt ath the moment as Mr damage says...

wait until they sit firmly at 0-0.25 (ie. no purple shades, ideally light blue if you use API test kit)
before reducing salt levels.

prolonged elevated nitrites can have a negative long term effect on fish
(ie. physical damage)

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