Ammonia

Ive got a 120ltr tank - external fluval canister filter - stock with malawis and full of rocks... fish seem healthy but my ammonia is high and I just cant seem to get it down. Im using zeolite in the canister which went in last Monday - also AM guard and Bacteria booster. Im doing small water changes and hoovering the gravel to make sure there is no waste anywhere... I stocked with 6 malawis straight away so as to spread the aggression.. there doing really well but today Ive noticed one of the males rubbing against the rocks, they are eating really well but obviously Im really worried about the high level of toxics. please can anyone suggest anything.

I was planning to do a 60 % water change but I think that might be a bad idea


Paul

To add to what Jesnon said - if you have Malawi cichlids, you will have a high pH. Ammonia is more toxic at high pH so you really need to get it low by as many water changes as necessary and as big as necessary. It is fine to do a 90% water change if that's what it takes as long as you warm the new water to the same temp as the old water so you don't shock the fish.
To give you an idea, at pH 8.0 and a temp of 25 deg C, even 0.5ppm ammonia is toxic.

Is there any way you can return the fish to the shop and do a fishless cycle? Maybe ask the shop if they'll hold the fish for a few weeks for you?

Zeolite is not really a good idea. Yes it will absorb ammonia but if you remove it all this way there will be none left to feed any bacteria so they won't grow. Then when it gets full there will be nothing removing ammonia and the level will rocket.
If the AM Guard you refer to is one of those products that detoxifies ammonia, bear in mind that the effect lasts only around 24 hours.
The bacterial booster probably won't do much as most of them either contain dead bacteria and/or the wrong species on nitrite eating bacteria. But you might be lucky and the one you used might have an effect.


If you want to keep the fish, you are in for some hard work I'm afraid. Test the water a couple of times a day and do water changes to keep the ammonia low.

The good news is that nitrite is less toxic at higher pH. Once you get to the stage where ammonia stays low but nitrite is high, the fish are in less danger than in a tank with low pH. The effect of nitrite can be mitigated by adding plain salt to the tank and Malawi cichlids are fish that can cope with salt. Once you get to that stage, I'll let you know the amount to use.



And just to add that I'm assuming you have hard water with a high pH because you have Malawi cichlids.Iif you have soft acid water, they will not do well.

How did you cycle the tank? Use of the phrase 'let it cycle' sounds as though you just let it run for 2 months. Did you add ammonia and wait until both ammonia and nitrite had dropped to zero before getting fish?

The buckets of cycled water won't help much, I'm afraid. There are virtually none of the right kind of bacteria free floating in water. The ones we need to remove ammonia and nitrite grow tightly bound to the biofilm which coats every surface in the tank. These bacteria grow mostly in the filter as that's where their preferred conditions are found but they also grow on the glass, decor and substrate.

Keep testing the water and doing water changes when necessary. You can relax when both ammonia and nitrite stay at zero without water changes - well except for the routine maintenance water changes.