Help - Lost 5 Fish In 2 Days, What's Happening

[Luvmygeetars]

Hi

I have (well had now) a 220L community tank of tropicals with the following:

2 x halfback angels
2 x marbled angels
2 x Pakastani loaches
2 x spotted catfish
1 x gold gourami

Since I reduced my stock levels months ago, I have had a very peaceful and clean tank, but in the last 2 days a brown algae has appeared on my tank glass and plastic plants and 5 of my fish have died. I have checked with my test kit and got the following
PH 7.6
Ammonia 0.25ppm
Nitrite 0
Nitrate 0

I took a water sample down to the LFS today and they said basically the same thing - " your PH is a little bit high". They couldn't offer any suggestions at all.

I did my regular fortnightly water change last weekend, so it is not due again for another week. I just don't know what would cause the algae bloom and for my fish to just start dieing like this.

Any suggestions would be great!

Cheers

Brad

 

[N0body Of The Goat]

"I did my regular fortnightly water change last weekend, so it is not due again for another week."

While not conclusive as the cause of the deaths, the above statement does not sound great. How much water are you changing every fortnight? Because of fry, I currently have five tanks running at the moment (ranging from 54l to 540l) and each one gets a minimum of a 50% water change (fry tanks usually get at least two changes) using two buckets (totalling 25l) and a gravel syphon, it is a big responsibility and takes up a lot of my time outside work.

How often do you check ammonia and nitrite levels? What is your course of action when you get a 0.25mg/l reading?
Did you fishless cycle this tank, or were some of these fish involved in a fish-in cycle?

A stable pH is better than one that fluctuates all over the place, your soft water fish might not sucessfully spawn. At higher pH and temperature, the amount of ionic ammonia increases, so a 0.25mg/l reading in a temperate 20C soft acidic water tank is going to be less critical than an alkaline tank at 26C.

 

[Xraymark]

Shouldn't read any ammonia in tank. 0.25 and above is harmful to the fish.

Probably should do a 50% water change bring that down and keep monitoring if it comes back up.

 

[snazy]

As Xraymark suggested, water changes is best now to keep the ammonia as close to 0 as possible.
You may as well have had higher ammonia readings and did not notice. Brown algae also appears when there is ammonia in the tank and should go away once your minicycle is sorted.
Make sure you do a good gravel syphoning to remove any stuff that may have caused your ammonia spike.

 

[balajake]

water changes should really be done weekly.

 

[mark4785]

Increase the frequency of your water changes to once per week; remove between 20-40% of your water. You may wish to do this exercise multiple times per day while you have detectable ammonia.

Its important to do water changes at this frequency as if you don't it can contribute indirectly to a unstable PH and a dirty filter; an excessively dirty filter will produce various nitrogens like ammonia and nitrates that will feed and therefore support algal growth.