Cycling Or Not Cycling ?

[sthomas048]

Hello Every1,

Ive been cycling my tank and would like people's opinions on whats happening. My tank has been cycling for 6 weeks next Wednesday, at the end of week 2 i added 5 Zebra Danio, two weeks later i added 7 Colombian Tetra. I didnt not do any test on the first week my tank was cycling, but since then my readings have stayed the same apart from the PH. Ammonia 0. Nitrite 0. Nitrate 5. PH started at 7 and is now 6. I have noticed some brown spots and greeny "dirt" on the inside of the glass and there is some fuzzy brown stuff on my Java Moss (algae ?). I have Salvinia floating on the surface and some Java Fern/Moss on some driftwood. I did do a 20% water change during the 3rd week.

So what is happening ? Is my tank cycled ? I know this has to be the most commonly asked question on this forum !

 

[Miss Wiggle]

can you explain what you have done to cycle the tank, what (if any) products you have used. or did you just fill the tank, turn everything on and wait a week before adding the danio's? have you done any water changes?

can you also tell us what test kit you are using, and have you tested your tap water, if so what are the readings?

 

[sthomas048]

Hi Miss Wiggle,

Thanks for your reply. Yep, thats pretty much what i did, i just set everything up in my tank then switched it all on. Added the Danios a week or so later. Ive also been adding "Cycle" once a week for the last three weeks. I did a 20% water change during week 3, due to concerns over dropping PH, which ive since learnt was in error. Im using the Hagen Nutrafin kits. Also to verify what the Hagen kits were saying ive started using the API kits - with the exact same results.

My tap water reads -

PH - 7
Ammonia - 0
Nitrite - 0
Nitrate - 0
GH - 20mg/L
KH - 10mg/L

 

[Miss Wiggle]

what size is the tank, to cycle with fish you would have expected to see an ammonia and nitrite spike, then the nitrate would have gone up. to have ammonia and nitrite at 0 and nitrate so low is puzzling. it certainly indicates that all is well in the tank but i'm skeptical as I wouldn't expect to see those results at this stage.

have youy read the pinned topics on cycling? If not then I'd suggest you do, for information and to better understand the cycling process if nothing else.

 

[sthomas048]

My tank is 80cm X 36cm (54cms high). Its a Juwel Rio 125L. Yeah ive read quite a bit on cycling, thats why im so confused over my tank ! Perhaps its just that ive got a really slow cycle going on ? Thanks.

 

[aaronnorth]

you have algae, your kh and gh is low so it may cause ph swings which is causing algae.

 

[rdd1952]

What type media do you have in your filter? As mentioned, you should have seen and ammonia spike and later a nitrite spike. The fact that you still have no nitrate leads me to believe that you may have some type media that is removing the ammonia rather than letting the tank cycle.

 

[xxBarneyxx]

Why would PH swings cause algae? Not saying that it doesnt but have never come across that before and can think of no reason why it would so would be interested in reading more about it.

Green dust algae is common in pretty much every tank and you cant really stop it. Just wipe your glass down occasionally and it will be fine. You might want to look at adding crushed coral in a bag in your filter to help buffer the water and stop the PH from jumping about (its a good idea to replace the crushed coral every so often or give it a good rinse).

With regards to the cycling it is very stange. As Miss W said you would have expected to see ammonia and Nitrite spike at some point so its odd that it hasn't. It would appear that the tank is cycled but I would watch the water stats very carefully.

Salvinia is very effective at removing ammonia and nitrate from the water so if you have a lot of it it could explain no ammonia readings (though I'm not convinced). Only thing I can think to suggest is to just check it daily and makre sure the ammonia and nitrite stay at zero for a week or two before adding any more fish.

Edit: He does have nitrate, 5ppm. The water stats in the later post where his tap water so there is something going on. It might have just cycled really quickly.

 

[sthomas048]

I have the Juwel internal Filter which has white filter wool on top, then an active carbon sponge. then a nitrate removal sponge (just looks like a normal sponge to me) and then the fine and coarse blue sponges on the bottom.

2 weeks ago i added a Tetratec external filter (EX700) too - this one has white filter floss on top, then activated carbon, then Bio Filter Balls, then some filter foam and finally ceramic filter rings on the bottom.

Thanks guys for your help, much appreciated.

 

[rdd1952]

I missed the 5 ppm of nitrate. Thanks for pointing that out. I am also not aware of any connection between pH swings and algae. It does sound as your tank is cycled for the fish you have. Adding more sill still mean that the bacteria has to catch up which could be a slight problem as bacterial reproduction slows considerable as pH levels get near or below 6.0. You may have to work on getting the pH back up via water changes and/or adding buffering.

If I were you, I would remove the carbon, the carbon sponge and the nitrate removal sponge. They will all be saturated before long anyway and not doing anything. Replace the sponges with regular sponges and just forget the carbon. Most of us never use it unless it's to remove medications from the water.

 

[sthomas048]

rdd1952, when i did the 20% water change a few weeks back the PH increased to 6.5, so perhaps with weekly changes my PH will stick there ? Its mad that ive only done one water change isnt it ! I just figured as the nitrate is so low i dont need to do any ? I will take a look at the sponges in my filters over the weekend. Thanks mate.

 

[rdd1952]

You are right that one of the main purposes of a water change is to remove nitrate. In your case, with apparently little buffering capacity in your tap water, you will probably have to stick with weekly water changes to try to keep the pH stable. Don't get me wrong, the fish you have will probably be fine in water with a pH of 6.0 as most can easily adapt to any stable pH. I just don't like it when it's showing a reading that makes me wonder if it's 6.0 or actually lower since that's as low as the chart goes.

 

[xxBarneyxx]

As you have already mentioned even with low Nitrates there are still other reasons for doing regular water changes (keeping the water buffered, ph stable and removing disolved organics). With weekly water changes it might well keep stable. Give it a try for a couple of weeks and see how it goes.

I agree with taking out the chemical media (active carbon, etc). They pretty much all have their uses but unless you replace them regularly the are not worth the space they take up.

Rdd1952 also raised the important point that even if it is cycled you might still get ammonia spikes and mini cycles as you add new fish. As such you need to stock slowly and watch the water quality. If you see a big ammonia/nitrite spike then do a larger water change (this is the advantage of fishless cycling, you can cycle the tank and once its finished can pretty much fully stock it).

 

[sthomas048]

rdd1952, my Hagen test kit actually goes down to PH 5, my current reading is 6. Barney, as from this week i will commence with weekly water changes then. I have been closely watching my water quality over the last 6 weeks and i will continue to do so especially when i do decide to add more fish. I have been feeding my fish on flake food, but i do plan on starting on some frozen food once a week, this will probably increase the waste produced in my tank.

 

[rdd1952]

That's good that you know it is actually 6. My API only goes to 6 so if it were ever yellow, I wouldn't know just how low it was. Adding some frozen food once a week shouldn't have any effect on the waste. When I feed them frozen food, it is in place of the regular flakes, shrimp pellets and wafers not added to them.