Cycling using. Prawn

[Willba200]

Have two raw prawns in tank for last 24hrs
Ammonia has gone up as expected. Now do I leave the prawns as my water has turned a little cloudy. Nitrate and nitrite is at 0

 

[herp_mommy]

Leave them in until the ammonia starts to drop. Hopefully you have then in a nylon sock so they can be removed easily. The water should clear up on its own when cycled and you do a water change.

 

[Willba200]

Yes they are in a nylon sock. So I just leave them?

 

[TheTodd]

Yes. Leave them in. As they decompose, they create ammonia, which is what keeps the cycle going. In the end, you should have zero ammonia, zero nitrites and elevated nitrates.

 

[Timeplt]

Just about to start my first 40g saltwater tank. I chose to go with Dry rock for a few reasons but I have purchased a 20lb bag of live sand & looking youse shrimp or prawn to start the cycle. I'm looking for any advise to help get the cycle started.

 

[TheTodd]

Just about to start my first 40g saltwater tank. I chose to go with Dry rock for a few reasons but I have purchased a 20lb bag of live sand & looking youse shrimp or prawn to start the cycle. I'm looking for any advise to help get the cycle started.

Same thing...get a shrimp/prawn or two, put it in something (pantyhose) so it does not go all over inside the tank when it starts to decompose and throw it in the tank. Nature does the rest.

 

[Timeplt]

Finally started my tank 7 days ago. It's a 45 gallon but it slim & tall, not ideal for a reef but I like the look & it was a great deal from a friend. I chose to use a canister filter since I did not want to chance a hob skimmer or drill this tank since it's my first salt water. I got a Hydor slim skim and a power head for circulation. Started with 45 lbs Fiji dry rock, 20lbs of aragonite live sand (couldn't find dry at my closest local fish place). I did not want live rock because of a few parasites that my friends got in I their live rocks. I put 2 medium frozen shrimps in the tank, measured salinity, ph 8.0, Ammonia, nitrate & nitrite all were 0 as expected 6 days ago & all have increased as expected or rather quickly as of today. Today ammonia is 2.0, nitrite is between 2.0 & 5.0, Nitrate at 20ppm.
Seems to be moving along faster then I expected but I will wait till next reading to be sure.

 

[Willba200]

Speedy cycle, cool. Put my cuc in yesterday. Want to do it slow and right. Like you I've never done sw before. Good luck

 

[Timeplt]

Cycle

Wilba200, If all goes well with this tank I know I will be going bigger but I need to justify another expensive hobby to the wife with success of this tank first.

How long did your Cycle take & what size is your tank?

 

[Willba200]

Good question, I think it cycled after a couple of weeks because all tests showed nil. Then I put in 2 raw prawns and ammonia went up as expected. Then a couple of days later it went back down to nil. So I think it may have cycled before prawn went in. My tank size is 3ft 33 gallons.

 

[TheTodd]

At the end of a cycle, you should have nitrates. Everything can not be zero or something is wrong. The only way nitrates leave your tank after a cycle is by you doing water changes. Ammonia and nitrites convert to trates, so those will be zero.

 

[Willba200]

How long would it take to turn to trite /trates

 

[TheTodd]

A cycle typically takes about a month. Less with live rock/sand, but still a couple weeks I would guess. With a shrimp, you should get ammonia within a day or two and nitrites should follow soon after. Nitrates are the end result and those just don't disappear...they either lower by water changes or things like reactors or macro algae.

 

[Willba200]

Tank was cycling for about 3 weeks before prawns were added. With 50lbs of live rock and live sand. I have had to do a couple of water changes (1 last week) just to get salt levels down which is now spot on. Tested water yesterday and all was nil. I hope I have cycled!

 

[Willba200]

All in all it was about a 5 week cycle. From shop to tank was about 1 hr. So rock was not out of water for long. After ammonia spike using prawns and then ammonia turning to 0 they were left in for another 4/5 days. All results still showed nil. What do you think?

 

[Willba200]

The Todd . You were right!....... Reason I had no nitrate readings were because I was not doing the test wrong! Basically I was not shaking the bottle enough. My readings are about 30ppm! Trouble is I thought I had cycled so I put in the hermit crabs and snails. Will they be ok? Now in process of doing my first salt water mix/ water change. Should I do this once a week or daily to get nitrate down to 0.

 

[TheTodd]

I do changes as needed. Nitrates don't need to be at zero, but you want them low. It is ammonia and nitrites that need to stay zero, which they should as long as it is cycled and you do not increase your bio-load too rapidly.

 

[Willba200]

I feel like a right idiot as you and others were saying that I should have nitrate present. Turns out I did and was not shaking the bottle enough:/ will check parameters tomorrow and do another water change as I only done 20% earlier. On the plus side I had to do my first salt mix this evening and got it spot on, so that's another worry off my mind.

 

[TheTodd]

As long as the next tests come out the same, you should be fine. Once a tank is stocked, even partially, you should have some Nitrate present. That is the result of the ammonia turning to nitrite, which changes to nitrate. It might read zero for a day or two, but if ammonia is being added (by waste and or deteriorating food), then nitrates have gotta appear.

Make sure you add fish slowly. With past tanks, I usually went one fish, maybe two small, every three to four weeks. If you add too quickly, the ammonia overwhelms the beneficial bacteria and they can't convert it to nitrite quickly enough. You get ammonia readings that way. Those BB numbers will increase as more ammonia is added, they can only do it so fast though. Slow wins the race.

 

[Timeplt]

I too found out I was doing my Nitrate test wrong. Found out I was not shaking bottle #2 enough or at all lol. I performed all my tests correctly yesterday & ammonia is about 0 , nitrite is at 2.0 & nitrates at 40 ppm. It's been 11 days since I started the cycle process.