Small nitrite spikes and keep needing ph buffer

[bpeitzke]

We have a 40-gal SW FO tank with 2" CC substrate, no LR, Fluval 204 filter & protein skimmer. Been keeping it at 78F and 1.020 SG; just bumped up to 79-80F and 1.021. Six fish - damsels, a dwarf angel and a fat little puffer. It's been pretty stable, but we lost our Emperor Angel to fin rot last week. We've started getting small nitrite spikes recently - not high, about 0.3mg/l. We add Amquel + which knocks it down. Ammonia stays zero; nitrates steady at 5 mg/l. Also, I've noticed the ph trends toward the low side of 8.0, and we seem to need to keep adding a little ph buffer.

Shouldn't ph stay stable other than at water changes? What could be causing these small NO2 spikes? E.g. I got a recommendation that CC substrate traps debris more than sand, and tends to promote nitrite/nitrate buildup. Is CC bad? Do we really need to change to sand substrate?

And what about adding some LR? Would it help with these little problems?

Grateful for any advice

Bob Peitzke
SW newbie (well, maybe a sophomore now)

 

[fishfreek]

Honestly your tank sounds over crowded even after the angel's loss. The emperor angel would have outgrown that tank aswell as this is a large angel not one of the dwarf species.

The PH issue could be a direct result of increased levels of CO2 in the tank. If you check the PH in the am before or soon after the lights come on how does the PH change from testing it just prior to when the lights go off? There is a normal swing of 0.1 or maybe even 0.2 thruout the day as the CO2 and O2 levels.

Another item to check is your alkinity. The alkinity level and the PH level are somewhat tied together in that a balanced alkinity will tend to offer you a more steady and consistant PH.

Do you gravel vac the CC? Gravel vacing the CC should help keep nitrates to a managable level. Nitrite should not exist in an established tank unless your overstocked or overfeeding. Did you medicate the tank at all for the fin rot?

 

[bpeitzke]

Crowded tank, alkalinity, ph, nitrite spikes

>>your tank sounds over crowded even after the angel's loss<<

So I've been told by several experienced people in these forums. I believe it. Trouble is, our adult daughter, who started the SW tank, trusts an LFS guy who says we can have more fish than the "one fish-inch/5-gal" rule of thumb (that we're still over). Such politics complicate our efforts to maintain the tank while she's away (sigh).

So ph is affected by CO2/O2 balance, which is affected by light? Interesting. I wouldn't have guessed that, since those molecules have no H-ions. Hmmm .... We did test it this morning, dawn-ish. We'll start watching for differences between AM/PM tests.

>>alkalinity<< I thought ph was a direct measure of acidity/alkalinity, the latter being the base side of the ph scale. I understand that dissolved salts are not the same as base ph, which I believe is a predominance of HO ions. But I think you are saying that more dissolved salts tend to increase baseness - higher ph - right?


We do try to vac the CC a little at water changes, but using our simple siphon, we don't get much. Better way? Not another expensive gadget I hope (

No, we didn't medicate the tank. I understood what that would do to the beneficial bacteria culture. We medicated him with Maracyn 2 in a quarantine tank, but I think we waited too long, and he was too far gone.

Appreciate your advice.

Cheers,

Bob

 

[fishfreek]

Its acutally the photosyntsis of the algae in the tank that uses up the CO2 and produces the O2.

 

[fishfreek]

I would have posted this above but I needed to look them up real quick.

Here are two excellent articles written abotu PH and Alkinity. I admit they are rather technical and I really have a hard time grasping them for more than just a few minutes.

pH vs. Alkalinity in Reef Tanks

Solutions to pH Problems

 

[bpeitzke]

Thanks for article pointers

I've printed both articles for evening "light reading".

Thanks.

) Bob