Problems with Nitrates and pH.

rsteph

I'm having a little trouble all of the sudden with balancing my tank... For the first 4-5 months everything ran smooth, now I'm getting a Nitrate spike, and my pH is running a little low.

I've got a 20 gallon tank, with about 18 lbs of live rock, crushed argonite substrate, and a carbon filter designed for a 30 gallon tank. I don't have a Protein skimmer yet, I'm trying to find a decent one within my price range (~$50-$60). My tank currently has 1 common clownfish, 2 flame firefish, and 1 turbo snail.

Ideally I'd like my tank to have the 3 fish it has now, 3 snails, 1-2 small crabs (blue legged hermits or something), and a skunk cleaner shrimp. Maybe a starfish if I can really get things working right - that would be the end of inhabitants.

On March 23 I did a water test, here were my readings:

Nitrates ppm (mg/L): 80
Nitrites ppm (mg/L): 0
Chlorine: 0
Alkalinity ppm (KH): 300
pH: 7.8
Ammonia ppm (mg/L): 0.5
Specific Gravity: 1.026
Temperature: 79 F

I replaced my filter and did a major water change (about 40%). I tested my water tonight (4/2/08) and got the following readings:

Nitrates ppm (mg/L): 60
Nitrites ppm (mg/L): 0
Chlorine: 0
Alkalinity ppm (KH): 240
pH: 7.8
Ammonia ppm (mg/L): 0.125
Specific Gravity: 1.025
Temperature: 79 F

I've done water changes at least once, sometimes twice, a week; and larger water changes than I usually do. I can't seem to get my Nitrates to go down though, they hover between 50-80 for the last 3-4 weeks. Does anyone have any suggestions on what I can do to fix my Nitrates problem and/or raise my pH a little?

My Live rock is going really well, it's probably 50-60% covered with purple coraline algae. And I've never really had an algae problem, or any other issues. Would a protein skimmer help with my nitrates problem? Would it be worth trying to get some of the chemicals designed to lower Nitrate issues? Would adding more cleaning crew right now (i.e. snails and crabs) help or hurt my water problems?

Any advice would be greatly appreciated. This is my first saltwater tank, and at 5 months in I'd say I'm still fairly new to things.... Thank in advance for any help you can offer.

Nereaga

Hey Steph,

The first couple of months do go easy. After awhile things start to get used up and drop. Your pH just needs a little buffer. I use Reef Builder by Seachem, it raises alkalinity and stablizes pH to around 8.3.

Your NitrAtes could be from slightly over stocking. Three fish in a small 20g tank is pushing the bio-load, IMO. I might be inclined to trade in a fish here.... Just me.

A skimmer will help with NitrAte removal for sure, how much???? I don't know. Your price range will severely limit you in finding anything that will work even decent. About $100-150 could get you a used/new Aqua C Remora.

Do you have an excess build up of detrius in your tank or on your rocks?

Do you keep the carbon filter cleaned regularly?

Water changes will give you temporary relief as you know. You still need to find the source.

Brad

unclejed

Hi rsteph, more details please. What type of filter do you have i.e. hang on back, canister etc. and what do you use in the filter. Also, from the amonia readings, your tank is cycling again for some reason. Have you added anything to the tank, rock, sand etc. Also, your reading for alk sounds more like low calcium. KH reading for alk will be 8-12 (proper range) so I am confused as what your reading is. Have you checked magnesium and phosphate yet? Try to address these issues I've raised and let us know.

chadf

The alk is in ppm. It can be expressed in meq/L, dKh, or ppm.

Loman

Expanding on what Nereaga was saying, Do you clean any sponges etc. in the filter. Clearly you have a strong source of Nitrate and I suspect that it is just now building up. Places where detritus builds up is the places I would start looking. Also I would be concerned with the ammonia level as well (probably more than nitrates). IMO you want an ammonia level of 0. DId you have the ammonia level at zero after detectable readings?