Advice would be REALLY appreciated

[boxman]

Hmm, where do I begin? From the start I guess!

I have 2 main tanks in use, 22gal and 14gal (see sig for stock). I've had nitrate problems for about 2 months or so (in both tanks) and I've been using water from my LFS that is low in nitrate so I can use in a 20% water change which I have been doing for the last month. Nitrates seem to be settling more now but are still higher than 0 three months ago.

The levels right before the water change today in the 22gal is
PH 7.6
Ammonia 0.1
Nitrate 30.0
Nitrite 0.0

In the 22gal I lost my gold nugget pl*co on Saturday and 4 oto's today (I have 2 left). None were attacked.

In my 14gal I lost 5 cardinal tetras over a period of 48 hours (literally died rather than were attacked). I have 3 mollies and a betta remaining which seem to be happy enough.

I have a fluval 404 in the 22gal with UG & powerhead and the 14gal has a 204.

Water changes are done every 2 weeks - 20% and I use dechlorinator to the recommended dose and stresszyme to the recommended dose.

I feed the fish every other day at sensible levels and I was feeding 1.5 algae tablets or cucumber three times a week.

Any advice would be appreciated. Thanks

 

[The-Wolf]

ammonia should always be zero
I would perform your water changes weekly as a normal thing, rather than bi-weekly.

is there anywhere on the island that sells Sera products?, if so go and buy some ammovec, that should boost your Nitrosomonas bacteria and eliminate the ammonia

 

[boxman]

I have a test kit with the lowest reading being 0.1 for ammonia. I was under the assumption that was the lowest it could go.

I haven't seen that brand here to be honest.

I have a de-nitrate pouch which does seem to be slowly working as I said earlier.

 

[yuedarklord]

How much fish do you have in each tank? And what kind?

Your pH may be too high for some of the fish.

Try lowering it around 7.0 ish

 

[WILDER]

What's the nitrate reading from your tap.

 

[tttnjfttt]

Your pH may be too high for some of the fish.

Try lowering it around 7.0 ish

I doubt it is the pH. Most fish adapt to whatever the pH they are in. The biggest worry with pH is rapid swings.

What has the temperature been in your tank lately? Could that be going crazy?

Also, is there any chance any chemicals got put into the tank or anything sprayed around the tank? What about your family/roommates? Are the tanks kept in the same area of your house?

 

[CFC]

I'd say the problem was the infrequency of water changes, i would be changing 20% every week.

Another factor you havent mentioned is temperature, with the warm weather oxygen levels are lowered, the warmer the water gets the less dissolved oxygen it carries. With the infrequency of water changes dissolved organic solids in the water column are able to build up inbetween and use up oxygen as they break down, lowering the oxygen levels further. All the fish you have mentioned come from fast flowing well oxygenated streams and rivers and are unable to tollerate low oxygen enviroments well.

My advice is gravel vac and water change 20% weekly to remove dissolved organic solids before they build up and rinse your filter media every two weeks to keep the ammount of trapped crap to a minimum, under maintained filters are the major cause of nitrate build up.

 

[boxman]

Ok, tank temps for both tanks are 26oC and both are well oxyginated.

The 22gal has a powerhead that blows bubbles the length of the tank and the surface is fairly displaced by a 1.5' spraybar.

I know what you're saying CFC about the frequency of water changes but I'd kept this tank at absolutely perfect levels and 100% survival of fish whilst feeding them every day and more heavily stocked than it is now and only a bi-weekly water change and filter clean.

Fish from fast flowing waters - well they do have a 404 in a 22gal - hope that's fast flowing enough!!!!!!!!!!

Agreed about the main problem is a dirty filter - my 404 is DEFINATELY not dirty, that's for sure! I could probably leave it running for a few months without a problem (not that I would).

Yes the weather is warmer here now than 3 months ago but tank temp is no higher than 1oC than usual and it fluctuated around that anyway.

For stocking level see sig (bear in mind there was a gold nugget and 4xotos in the 22gal up until weekend).

All the fish in the tank are still small - I have the LFS' guarantee they'll take my BGK off my hands as it's worth more to them larger than when I bought it (incase I get the 'you're overstocked with just the BGK' speak - which is valid I know!)

Thanks all


(Also, PH from tap is same as tank, 7.6)

 

[WILDER]

I agree with cfc the only way to keep nitrates down is weekly maintance, i do all my tanks twice a week, but it's not for everyone, the waste of the food could be laying rotting away in area's in the gravel, best to give gravel a stir ever few days as it can cause bacteria to breed more faster and cause desease.

 

[boxman]

Thanks guys, will try that.

Still, considering the nitrates have gone down recently it's strange the fish die now when it's going down rather than when it was more like 75.

Comprehensive advice as always - thanks!

 

[CFC]

Im suprised you have managed to keep the tanks running at 26 even throughout the hot weather, even my largest tanks have been running at around 28 without heaters.

Dont look too much into nitrates, here they come from the tap at 50ppm and by the time its sat in the tank for a week it has risen to 60-70ppm. All but the most delicate species can easily tollerate nitrates up to 100ppm. All too often pH and nitrates get blamed for sudden fish deaths when in reality it is more often than not something else entirely, i guess its just that those can be easily tested for where as REDOX values and DOS content require expensive specialist equipment.

 

[Boxcar Muzzdogg]

I doubt it is the pH. Most fish adapt to whatever the pH they are in. The biggest worry with pH is rapid swings.

Exactly. I know you mentioned that you thought the test strip only went down to .1, but in a properly cycled aquarium the ammonia should be at 0. If it is really true that your ammonia is at .1 then your biological filtration may not be where it should and you should try to figure out the problem in the filtration (perhaps just not enough) and how it should be fixed. Also, as others have said, if your having problems keeping the nitrates down then performing water changes more frequently is what you need. There may be a problem contributing to the high nitrate levels so keep looking while you are doing those frequent water changes.