Cycling a Brackish tank

[Chizzow]

Im currently cycling a 40 gallon brackish tank. Its been cycling for about 3-4 weeks now and Im still getting readings of:

Ammonia (0.6 mg/L)
Nitrite (0.1 mg/L)
Nitrate (5 mg/L).
1.010 S.G.

My question is normally with freshwater setups, ammonia will peak fall, then nitrites will peak fall and finally nitrates will peak and fall. However at this point, my brackish tank have all three elements evident. Is this normal for brackish water? If so, approximately what stage of cycling am I in?

thanks!

[Melody]

As far as I know the nitrogen cycle is the same in both freshwater and brackish tanks, for the purposes of your question anyway. Trace readings across the board aren't unusual, but one is normally significantly higher if you are indeed cycling (an aquarium is always cycling actually - no wonder cycles confuse people). It looks to me like its either settling down or not progessing, more likely the latter.

How are you cycling? How are you producing ammonia to feed the bacteria?

[Chizzow]

As far as I know the nitrogen cycle is the same in both freshwater and brackish tanks, for the purposes of your question anyway. Trace readings across the board aren't unusual, but one is normally significantly higher if you are indeed cycling (an aquarium is always cycling actually - no wonder cycles confuse people). It looks to me like its either settling down or not progessing, more likely the latter.

How are you cycling? How are you producing ammonia to feed the bacteria?

Its been on a standstill for the past week or so. I have a couple of molly's in there. Im just debating whether I should do a 50% water change since its not progressing or just leave it.

[hp10BII]

What's your pH? I was fishless cycling a tank a few years ago, seemed like it took forever to cycle when I decided to take a pH measurement - it was off the scale, pH crashed, it was under 6. With all that nitrifying activity, it used up all carbonates so I couldn't tell what stage of cycling it was at because I still get Nitrite and Nitrate readings.

If your pH crashed, add some buffering material, that helped me. That's why I prefer fishless cyling with household ammonia, you could control your ammonia content to see where you're at in the cycle and spare some fishy lives.

[Chizzow]

What's your pH? I was fishless cycling a tank a few years ago, seemed like it took forever to cycle when I decided to take a pH measurement - it was off the scale, pH crashed, it was under 6. With all that nitrifying activity, it used up all carbonates so I couldn't tell what stage of cycling it was at because I still get Nitrite and Nitrate readings.

If your pH crashed, add some buffering material, that helped me. That's why I prefer fishless cyling with household ammonia, you could control your ammonia content to see where you're at in the cycle and spare some fishy lives.

its sitting at 6.6

[Melody]

Sorry if I missed the answer somewhere, but have you seen any spikes at all yet? I'm just wondering if its slow because there's not enough waste being produced to cycle a tank that size.

The good thing about fish cycling or using filter media, gravel, etc, is that you can end up with a more stable tank at the end of the cycle because you're also colonizing the bacteria which breaks down solid waste. There's a name for that bacteria but I probably couldn't spell it even if I could remember it...lol...but I can find it if you want to look into it. It does take diligent management and a good eye for trouble, but the fish needn't suffer if you do water changes and 'manage' the cycle rather than just watching it happen like you would with fishless cycling.

I wouldn't do a water change if nothing is happening, but I'd keep a very close eye on the parameters. Mollies are very sensitive to mean water conditions in my experience, so they should be good indicator fish for you.

This should in no way dismiss what Mr. hp10BII suggested, its just that chemistry isn't my strong point so I'm not going there...lol.

[Chizzow]

The ammonia peaked during the first week and went down a bit, while the nitrite and nitrate peaked and dropped. The readings I have listed in the first post have been stable for over a week. It doesn't look like theres any changes whatsoever, which is why Im confused.

The molly's seem to be doing just fine, but I dont want to move my toadfishes into that tank until ammonia and nitrite are at 0.

[Melody]

You must be coming to the end then, but yes, it is odd that its not at zero. I'd take that to mean that not enough bacteria has reproduced and you're mini-cycling. Can you put a handful or two of established tank gravel in there or filter media? It might give the bacteria the boost it needs. It is still early in the cycle really. I agree that you should wait, especially for a larger fish. That's my 2 cents anyways.

He's going to love it in there - what size is his tank now?

[Chizzow]

there in my spare 10 gallon which receives daily water changes at the moment :no:

[Melody]

Ah, I can see your dilema. I didn't realize there was more than one. I have an empty 10G that you could borrow if you want to split them up, but you'd also have to do a lot of water changes on that since it would be new. Fish are fine crowded temporarily as long as there's enough oxygen and the maintenance is stepped up to compensate, which it obviously has been. I think they'd be happier there than they would be in an unstable tank that could spike any second. They're lucky to have you fussing over them so much!:smile:

[Chizzow]

Ah, I can see your dilema. I didn't realize there was more than one. I have an empty 10G that you could borrow if you want to split them up, but you'd also have to do a lot of water changes on that since it would be new. Fish are fine crowded temporarily as long as there's enough oxygen and the maintenance is stepped up to compensate, which it obviously has been. I think they'd be happier there than they would be in an unstable tank that could spike any second. They're lucky to have you fussing over them so much!:smile:

So far so good. The 10 gallon has an aquaclear 70 hooked up to it so filtration wise its doing pretty well. Their still eating as usual so I guess their happy. Toadfish arent active at all, which is why most people keep them in a 29 gallon. However, just to be extra nice I got them a 40 :smile:

Oh I should mention that I did use old filter media etc to help boost the cycle process, however because this is brackish, most of the bacteria was probably killed by the salt.

[Soggybottom]

This isn't terribly useful info, but last time I cycled a brackish tank, it seemed to take forever and be more of a pain than freshwater. I was doing twice daily 50% water changes for almost a week at one point to keep nitrite reasonable. I think I was at about 80% occupancy and 200% filtration following freshwater rules for stocking density. Saltwater levels would have been better...It was not an ideal situation, but it's hard to find people to babysit brackish fish.
I generally throw a lot of plant material in a fresh tank which I guess got me thinking it was always easy, but thats not really an option if your salinity is above 1.005.

Theres gotta be a plant that handles salt levels around 1.010, eelgrass or something, but I've never seen anything for sale...

[Chizzow]

I read that anubias do fine in brackish tank because of its thick leaves. So far mine look fine and are growing.

[Soggybottom]

Right on... how long has it been in there?
I have some anubia but not enough to risk until you guarantee it's safe;)

I bought a mangrove bean on Saturday, can't wait to see how that works out...

[Chizzow]

I've had the anubia nana's in there for over a month and its still nice and green, sprouted a few new leaves too!

keep us posted on how that mangrove pod does :D