Fishless Cycle

[MrPurplePickle]

Howdy Guys,

Does anyone have any experience doing a fishless cycle using a dead prawn?
Unfortunately here in Aus, it is extremely difficult to get your hands on ammonia.

I read somewhere you can use a rotting prawn as the ammonia source.
Problem is, how do you control it? When do you remove the prawn? Will adding another make it quicker?

I've had one prawn in for 10 days, added another prawn so 2 for another 10 days.
I haven't been able to test for ammonia etc until tonight (dodgy online retailer )

Anyway got a API master test kit (drops)
ammonia 1.0
nitrite 0
nitrate 10
PH 6.4

Tap water
ammonia 0
nitrite 0
nitrate 0
PH 8.4

Also KH seems non-existant, turned yellow on the first drop. Is this going to be a problem?
Any advice welcome.

 

[paulbr1]

I love prawns Mmmm. but sorry I don't know how many you need

 

[waterdrop]

Its going to "feel" very unsatisfying while you're doing it because there is very little control, but it can work if you hang in there. The main problem is that you can't control the amount and timing of the ammonia created by the prawn(s) and it can take longer than a typical fishless cycle, but give it lots of patience and you should be ok.

Now that you've got your kit you've at least been able to determine the first small significant fact: The heterotrophic bacteria (different from the autotrophic ones you're trying to grow in the filter) have begun to work on the organic molecules in the prawn and are creating ammonia from it. That's good. Don't worry so much about how many prawns or achieving perfect 5ppm levels like we do in household ammonia processes, it'll be difficult to achieve that. Definately monitor and log ammonia, nitrite(NO2) and pH every day (twice a day eventually.) I suppose as long as you are low (like the 1ppm you've got now) then adding another prawn won't hurt, but its probably more of a timing thing than a quantity thing and the ppm may shoot way high on you all of a sudden as the prawn rots more and more heterotrophic bacteria can get involved. Once you see it shooting up I'd take one out and be ready to do partical water changes if the ammonia level threatens to get to the 8ppm level (which may be unlikely as I would think it might take a very long time to do that.)

Your KH situation does sound like a problem with a measured 0KH and already seeing your high tap pH drop that much right away. Since you've got a KH test already you might consider going ahead and dosing a teaspoon of baking soda (not baking powder) per 50L as this should raise your KH without significantly raising your pH, so is a conservative and safe start. See what kind of KH you get from that and what kind of pH stabilization you seem to get and then consider dosing even higher in an attempt to move your pH back up into the 8 range where it started as that is ideal for maximum autotrophic bacterial growth. Be prepared for a couple of months of this, but your high pH should help and I'd set the temp at 84F/29C.

~~waterdrop~~

 

[Miss Wiggle]

WD is spot on with his advice above, what I'd suggest though as using a small pinch of flake food ground up every day instead of the prawn, i think it's just that little bit easier to control and measure.

basically you'll monitor everyday ammonia will rise then start to fall, nitrite will then start to rise and fall back and nitrate will relatively steadily climb up. when both ammonia and nitrite have spiked and fallen down to 0 give it a good few days to make sure they hold steady at 0 and then add fish.

because you don't have the accuracy and confidence from pure ammonia you'll need to build up your fish stock slowly, but it does sort of play in your favour time wise, you only need to build up enough bacteria to deal with a smaller number of fish, so don't worry about trying to get ammonia up to 5ppm or anything like that.

just so long as ammonia and nitrite have both definately spiked and fallen to 0 then you're safe to add a small amount of fish and build up slowly.

it's all about risk mitigation, this method is not as safe as a 'normal' fishless cycle with ammonia but it's a good step closer to safe than doing a fish-in cycle.

 

[MrPurplePickle]

Thankyou WD and MW.

Patience isn't a huge problem, it'll take as long as it takes.
WD...I'll get some baking soda in the morning, however I noticed on the API KH test pamphlet they mentioned
API Proper PH 7.0,7.5 to help increase KH and stabilise PH, ( what a suprise, pushing their own product )

Is that an option worth looking at or is it pretty much bollocks?

By the way, its 240 Litre tank.

 

[Miss Wiggle]

short answer is the API product is rubbish, it's also much more expensive than just using bicarb!

sure WD will furnish you with the longer answer if you want it!

He's much better with pH, KH and all that malarky than I am.

 

[waterdrop]

Don't listen to her, she's damn smart on all the stuff, just humoring me...

She's correct of course, you don't want to fool with any of those pH stabilizers. Even the baking soda (bicarb) is not a great thing to be putting in the tank, but in the case of fishless cycling, it doesn't matter because the "bacterial growing soup" is all "going out with the wash" at the end of cycling when we do the big 90% water change. That big water change is effective enough a clearing the decks for a fresh start of tankwater with the fish and the newly cycled filter will be running well by this point.

We tend to recomment the baking soda route to higher KH(higher total alkilinity really I guess)/pH during fishless cycling because its effect is instantaneous and allows you to see what you're accomplishing and have more control and feedback. What you're looking for is the following: when KH is at about 4 (degrees of german hardness) you know your pH will stay pretty stable for a few days. The KH reading serves as a "leading indicator" for you in that as you see it begin dropping below 4, you know you're going to get down to zero and have a pH drop unless you add more baking soda.

Its important to understand that all of this water doctoring is just going to go on during fishless cycling, not after you have fish. The cycling process creates acids that will push the pH downward harder than when the tank is running normally. Hopefully your tap water will turn out to have just enough natural hardness and/or pH to maintain things when you have fish. If not, then the route to raising pH with fish is entirely different. The preferred way then will be to use a bag of "crushed coral" in the filter, so that KH and pH will be very slowly raised and gently maintained. You can get all the details of that advice later if you need it.

~~waterdrop~~

 

[MrPurplePickle]

Well what do you know...
The company I work for has a dyehouse for dyeing wool, popped over there this morning 15 litres of 25% Ammonia Solution sitting there doing nothing.

Now at least the prawns still in the fridge can go a better use, the BBQ

 

[fatheadminnow]

Some very good advice from WD and MW...Even I learned something from this thread!

Well what do you know...
The company I work for has a dyehouse for dyeing wool, popped over there this morning 15 litres of 25% Ammonia Solution sitting there doing nothing.

Now at least the prawns still in the fridge can go a better use, the BBQ

I love prawns Mmmm. but sorry I don't know how many you need happy.

MrPurplePickle, you might wanna call up paulbr1 for the BBQ...lol.

Sorry, I couldn't resist!

-FHM

 

[MrPurplePickle]

Okey Dokey...
Added the baking soda, 4 teaspoons, hope that wasn't to have been 1 teaspoon per 50 gal.
Tested 30min later

PH 8.0
KH 13
Will keep an eye on this.

Now I've removed the prawns, smelt like our local fish and chip shop.
(List of things to do No.1 : Get a new fish and chip shop. )

Anyway, ammonia is still at 1.0. Should I wait for this to go to 0, or add my found ammonia to bump it up to 5.0?

ciao

 

[pammy172]

Ammonia solution hmmmmmmmmmm What else is in it? Do you know?

 

[MrPurplePickle]

25% Ammonia.
75% Water.

Its not for cleaning or anything like that, its from a chemical company.
In fact, one of the ones I called when trying to source some, but they did'nt sell small amounts to any tom, dick, or purplepickle.

 

[pammy172]

Result then!!! And you won't need much of that at that strength! Nice one - way better than mouldy old prawn!

 

[waterdrop]

Yes, your situation will be much, much better now and a nice strong concentration like that will make for smaller syringe squirts and even easier "recharging" of the tank during fishless cycling. Just to check though, we assume you will start in low and use your test kit to bring your level up to 5ppm and then write down what the magic dosing amount was, right, you don't want to be going by numbers like the supposed 25%, as that could be way off from reality.

~~waterdrop~~

 

[MrPurplePickle]

No probs WD.

Dosed it up 4ppm last night.
I've noticed in almost every thread on here everyonr says 5ppm.
I find this interesting, since in my API master kit the ammonia chart goes yadda yadda 2.0, 4.0, 8.0.

Not exactly conducive for hitting 5.0ppm, is 4 ok?