Eliminating nitrates - water change frequency, bio balls, etc.

Pasfur

Yes, Mike, would recommend a 4'' - 6'' sand bed for you. In my tanks I have done almost nothing to help maintain the sand bed, as the natural movements of fish & fish picking at the sand, along with a healthy population of copepods and amphipods have been sufficient to keep the bed stirred. All of the problems I hear about I have never personally experienced. I only used a shallow sand be in my 180 to save money. Today, with Nitrates being a challenge, I wish I had gone with a DSB to begin with. However, in a FOWLR tank, keeping Nitrates low aren't high on my priority list.

Agreed on all points.

I would recommend that you log your test results. This will allow you to develop a pattern, based on your bioload and filtration, that helps you determine when to dose and how much. I personally at a buffer and calcium supplement. I aim to keep alkalinity at 10-12 DKH and calcium at 420-460pm.

Administrator

I had mentioned that I had 4 damsels proving themselves in a 10 gallon quarantine tank. One or more of the 3 yellow tail damsels remaining picked the 4th to death. The remaining 3 look fine, though. Is it possible that this only happened because they've been crammed together in the 10 gallon during their quarantine period and will be fine once they go into my 55? Or do you think I can expect them to enact a campaign of slow death on each other and other tank mates in the future since they've killed their tank mate?

I would hate to have to "donate" them back to the store I bought them from 2 weeks ago and begin the quarantine process over with new fish, but I'd rather that than go through all of the effort to get my aquarium right only to be plagued by little monsters if indeed that's what these guys are.

reefsahoy

i know this answer will kinda be off topic but they usually say if you get 3 or more odd numbers tangs they won't fight either. but from my experience they will eventually fight till you have one remainding. I figured right then and there that tangs can't count and if they could they definitely can't distinguish even numbers and odd numbers. i even saw this in a 900 gallon tank with many tangs at a lfs who eventually lost almost all their tangs. so i'm betting that damsels will eventually fight to the death unless one is female and one is male or unless the tank is big enough where they can hide. another thing to consider is if you put damsels in the tank you won't be able to add any other fish in the future because the damsels will attack and kill them once the damsels settles into the tank and removing those fish is difficult.

Administrator

Thanks, reefs. I wonder if the "rule" about an odd number of fish is so that an aggressive fish will always have multiple fish to chase and is therefore somewhat less likely to "catch" and inflict harm on any. Your assertion that fish can't count is quite controversial. Next you'll be saying that the Earth isn't flat.

Yeah, these damsels are definitely going back to the store since I don't want to have to worry about other fish I add to the tank. I thought I'd give keeping them a shot because I read in a number of places during my research that yellow tail damsels were among the least aggressive damsels (liveaquaria.com says it as well), but them nipping their tank mate to death put things in perspective. Fortunately they weren't too expensive.

I started a thread asking about non-aggressive fish I could add to to the tank (after quarantining each). Would you guys mind taking a look? What are the least aggressive saltwater fish?

reefsahoy

usually a good lfs will take back live stock for at least 1/2 price. the sell it at 100% markup. it not like you say is this fish "used" or has he been "opened" like a package, and to be honest with you , if i know a fish was from another hobbiest tank, i will have a better chance tol be successful in keeping him because he's used to captive life. So ask for credit you'll be surprised. the lfs loses alot of fish when they get them wholesale, your's have a much, much better chance to survive in the lfs tank!

Administrator

That makes a lot of sense, reefs, but this particular LFS doesn't give any refunds or store credit.

Do you think it's possible that one or more of the three remaining yellow tail damsels only nipped the fourth to death because they are in this 10 gallon tank together, and that they won't nip each other or a tank mate once they are moved to the 55?

Administrator

I actually got partial credit for the 3 remaining damsels yesterday. I got the impression that I wasn't supposed to, though. I brought home 4 blue/green chromis that are now in quarantine.

I've ordered 75 pounds of dry rock, so between that and the 30 - 45 pounds already in the tank (I wish I'd written down how much rock I bought each time) I'll have a total of 105 - 120 pounds of rock between the display tank and sump.

Pasfur

Glad to hear they gave you some credit on those fish. Nothing gets my blood boiling quicker than an LFS that doesn't appreciate the customer!

Administrator

Yeah, I was glad to get at least some credit from them for the damsels. We've spent a lot of money at their store since we first discovered it, so it's the least they could do.

I noticed when I got the chromis home that one of them had what appeared to be a large circular sore or wound on its side. At the time we weren't up to getting back in the car and making the hour long round trip again for a $5.00 fish, so I put it in the quarantine tank with the others and hoped it would heal up. I found it dead the next morning.

Anyhow, on the nitrate front, I went ahead and tested my water parameters again this morning, expecting to find my nitrates at less than the 10 ppm they were at when I tested the water before removing the bio balls from the wet/dry two weeks ago. I was under the impression that, especially without any fish in the tank producing waste, the bacteria in the live rock that is said to convert nitrates to nitrogen gas would have reduced the nitrates by some degree.

However, I found that the nitrates have definitely increased over the last two weeks and are now closer to 15 - 20 ppm. More concerning, though, is that the water tested positive for ammonia for the first time in years at .25 ppm.

I attribute the presence of ammonia to the lack of bio balls and resultant lack of aerobic bacteria. I was under the impression that bacteria in the 40 lbs of live rock in the tank would handle the ammonia in the bio balls' absence, though. I was especially surprised to find ammonia since there haven't been any fish in the tank since 8/7/10, more than a month now, and there wasn't ammonia at that time. I was similarly surprised to find that the nitrates had increased.

Since removing the bio balls, I have not added any additional rock or made any other changes except adding 2 peppermint shrimp. Does anyone have any idea why my nitrates have increased despite the removal of the bio balls and why I suddenly have ammonia despite the presence of 40 pounds of cured live rock and no fish producing waste? I am concerned that I may have made a mistake by removing the bio balls after all.

It looks like I'll be doing a water change when I get home from work since I don't want the crabs and peppermint shrimp in the tank to die, though that will make the ultimate impact of removing the bio balls more difficult to determine.

bearwithfish

it sounds to me as though your tank is beginning to cycle again as you are now relying on LR vs the bio-balls.... i would think that in a few days time things should level out and drop ....