How to cope with nitrite spikes & PH fluctuations?

[bpeitzke]

Well, we're still struggling with nitrite spikes and ph fluctuations in our 40-gal FO tank. In fact, we had a big spike after last water change / vacuuming session. It got up to 1.6, the danger zone as I understand it. I think it was caused by the vacuuming churning up waste food that had been lying quietly in the substrate. Plausible?

We have six fish, biggest is the fat 4" puffer who eats more than all the others combined. We've been feeding one pellet of frozen sponge-etc food and some flakes nightly. 2" CC substrate, no LR (yet), Fluval 204 filter. I know we are overcrowded with fish, but can't do anything about that due to family politics. So I'm trying to come up with ways to cope with this. Here's where I'm heading:

- Converted 2nd basket (of the 3) in the Fluval to bio-habitat. Now have 2 of biohab and one of charcoal (was reversed before). I hope in a month or so when bacteria colonize this, we'll have more bio-filtering.

- Planning to get some more CC to build up deeper substrate. Again, after a month we should have more bio-filtering, right?

- Thinking about adding some LR. Wouldn't this add some bio-filtering capacity?

Other questions:

- Am I on the right track in thinking that basic problem (aside from too many fish) is overfeeding?

- Will my attempts at increasing bio-habitate for bacteria help?

- Is the Fluval 204 too small for our tank? (Directions say 40-gal.)

- Would conversion from CC to sand help significantly?

Apologies for long post. Very grateful for any advice.

Bob Peitzke

 

[Fishboy-from-NY]

I would get one more filter in your tank I say a big wet/dry for you to have alot of bacteria colinization. Also, when you do the water changes, check to see if the water you ae adding, contains any checmicals that maybe harmful to your tankmates. You can also add Hagen-Cylce everytime you do you rwater changes in order to prevent Nitrite spikes. As for Live rock & more live sand, you are on the right step, But remember their is no such thing as too much filteration. The MORE THE BETTER

 

[bpeitzke]

LS vs CC?

As I said, we have a 2" CC substrate in our tank. Would we get a significantly larger population of the beneficial bacteria in a LS substrate vs same depth of CC?

Thanks.

- Bob P

 

[Fishboy-from-NY]

No because they benifical bacteria only stays on the top inch of sand anymoe would be anarobic bacteria which is bad. My go would be buy more live rock or go with more filteration

 

[bpeitzke]

Substrate depth; feeding policy

OK, no point in switching to LS. I'll just get enough CC to build substrate up to 2" all around (we have some low spots). And I'll get some LR to add bio-filtering surface area.

I'm working on convincing my wife that overfeeding is the main cause - per the feedback I've gotten from this forum. Puffer is the big problem. I'm suggesting that we feed the frozen sponge pellet only every other day, and continue the flakes daily. Does this sound like a good idea? She's afraid puffer will attack the other fish if he's too hungry.

- Bob P

 

[bpeitzke]

pH keeps dropping; NO2 keeps spiking

We've done several water changes the last two days, probably totalling 1/3 of the 40-gal tank. We get the pH up to 8.0 and the nitrites down, but next morning they're both out of whack again. E.g. my wife checked early this am and got pH = 8.0 and little NO2. I checked 4 hrs later, and found pH - 7.7+ and nitrites ~= 0.8 mg/l. We keep adding pH buffer (using Seachem now) and Amquel + for the nitrites - they help but seemingly only temporarily.

I'm going on the theory that our problem was caused by overfeeding, and that it just took a long time to manifest, and that solution lies in lighter feeding schedule and more water changes in the short term to get nitrites down. I'm guessing that the high nitrites are also driving pH down.

Am I on the right track, or could there be another cause?

TIA

Bob Peitzke