Found Ammonia, am I overstock?

[Linsanity]

I have a 46 gallon tank and I'm using a Cascade 700 external filter. My most recent water test shows a little ammonia which I never had before so I'm a little concern if I'm overstocking.
16 neon tetra
15 guppy (6 adults, 9 juvenile
2 danio
3 platy (2 adults, 1juvenile
5 cory
1 Chinese algae eater
3 otos
2 GBR
Added within 30 days:
2 SAE
1 redeye tetra
3 roseline
2 amano shrimp

[mistergreen]

Yup, the ammonia confirms it.

[DarkCobra]

I'd say your stock is technically still within accepted limits of the tank itself.

But I agree with Mistergreen that the ammonia is a clear sign that it's not within the limits of your biofilter.

Any time there's a heavy fish load, I strongly recommend a second filter. Otherwise, you're relying on a single filter to operate at peak efficiency 100% of the time, which is a dangerous assumption. Any blockage, malfunction, or just an overzealous media cleaning can result in ammonia showing up. Having a second filter gives you more headroom and redundancy. If one filter starts declining, the bacteria in the other one rapidly increases and takes up the slack.

[Linsanity]

Thanks giuys. I have two hang-on filters that I can use them as back up filters, hopefully it will solve the problem.

[BBradbury]

Hello Lin...

What's your water change routine? I have a similar number of fish in my 45 G, but remove and replace half the tank water every week. An aggressive water change routine will replace heavy filtration. The reason is, the water isn't in the tank long enough for pollutants to build up in the water before the next large change.

Just a thought.

B

[DarkCobra]

Last I read you were using DIY CO2, and had a BBA issue; which is often thought to be related to low or fluctuating CO2 levels.

The HOB will offgas some of your CO2. Probably nothing too drastic, but check your levels after adding the HOB to be sure.

I agree with BBradbury's suggestion for 50% weekly water changes, but not specifically for long term control of ammonia. It's better for the plants/biofilter to keep up with ammonia production on their own.

[LB79]

This. This is how every hobbyist should maintain his or her tank(s). Not necessarily a 50% water change, but yeah, doing at least a 25% water change a week will greatly help with keeping the nutrients down.

Originally Posted by BBradbury

Hello Lin...

What's your water change routine? I have a similar number of fish in my 45 G, but remove and replace half the tank water every week. An aggressive water change routine will replace heavy filtration. The reason is, the water isn't in the tank long enough for pollutants to build up in the water before the next large change.

Just a thought.

B

[Linsanity]

I've been doing 30% WC weekly.
I did the last WC on Sat but last night I saw the otos were sitting at the same spots for long time so my experience tells me there is something wrong then I did the water test and saw 0.25 ammonia, but the test was done 1 hour after I fed them, not sure if that makes them release more ammonia than normal.
I'm not feeding them tonight and going to do another test.

[CatB]

have you checked for anything dead in the tank?

[acitydweller]

You are definitely pushing the limit on the tank. no more livestock for you!

[Linsanity]

Originally Posted by CatB

have you checked for anything dead in the tank?

I sat there and counted all the fish and they were all alive, and only 2 otos are not active all others were still active and look healthy.

Originally Posted by acitydweller

You are definitely pushing the limit on the tank. no more livestock for you!

I know... specially the small ones are growing up. I thought the tank size is good for this number of fishes

[Linsanity]

I tested the water again last night and ammonia was still 0.25 so I did a 40% WC, looks like I got to keep testing everyday until I see 0 for 3 consecutive days. I checked the filter and found it was turned to 90% after I dose ho2o last time, so I turned back to 100%, I also added one hang-on filter, let's hope it will help.
What else should I do if I still see ammonia in the next 3 days? Does adding a powerhead will help?

[DarkCobra]

Sure, the tank is good for that number of fish. And should still be good for when the juveniles grow up, or even for a few more carefully picked additions which you just can't do without. My 46G is a little more heavily stocked than yours.

Theoretically, it could hold much more, like the tanks you've probably seen at LFS which are sometimes jam-packed; they have gigantic biofilters on those to keep waste products under control. But that's not necessarily a happy and stress-free environment, as fish like to have space and quiet times.

Still, we can learn something from the LFS' example. On your 46G, the Cascade 700 is rated at 65G/185GPH. On my 46G, the first filter is a Magnum 350 canister rated at 100G/350GPH. The second filter is an Aquaclear 70 HOB, rated at 70G/300GPH.

But all of these ratings are idealized. Real-world performance is always less, and drops further as media gradually clogs. Ask yourself an honest question - how much can the flow of a filter drop before you're likely to reliably notice by looking at the tank? For me, I'd say it's about 50%. Add in the other concerns I mentioned in my previous post, and it's easy to see why I overfilter at 369% of the manufacturer rated amount.

Setting aside biofiltration for a moment, planted tanks also need more flow than unplanted tanks. Especially when you get into CO2 injection. CO2 moves very slowly through water on its own. In still water, it's only 0.0016 mm2/s, like molasses moves in winter! To make it worse, leaves deflect flow. And water in direct contact with leaves acts a bit like molasses itself, sticky and unwilling to easily move. Put all this together, and it puts plants at a disadvantage. If you could see with your own eyes the CO2 concentration at any point in a tank, you'd see a distinct layer about 1mm in thickness covering the surface of each leaf where CO2 is much lower, because the plants consume it faster than it can be replenished. This is called the Prandtl Boundary, and the CO2 level in it is the real CO2 level available to plants, lower than and regardless of the CO2 level in your tank as a whole. The only way to partially overcome it is with much stronger flow than a filter rated strictly for your size tank can provide. Typically we want at least 10X the tank volume per hour - for a 46G, that's 460GPH.

Which goes back to your question about the powerhead. It's not a biofilter, and will do nothing for your ammonia levels directly. But a similar boundary layer exists for all nutrients, to varying degrees based on how fast that particular nutrient travels through water. So if you're flow deficient, a powerhead may indirectly reduce ammonia levels by helping to carry it to plants which will consume it. As well as making for happier plants overall, as long as the flow is fairly uniform; and not so strong that it stresses plants/fish.

But you should be ok in three days with the addition of the HOB. If not, let us know.

[jcgd]

The roselines and algae eater get a bit big for that tank, 5-6" or so. Roselines prefer more room or they get pushy.

[roadmaster]

Much good information has been shared.
Were it me,, I might consider feeding less frequently and or, offering less.
Would also consider adding more plant's if there is room ,for they take up ammonia/ammonium quite quickly.
Would also consider larger weekly water changes.
Would keep filter's cleaned regularly (monthly).