Test Kit

Question
Richard,
Need ur advice (once again :P) regarding test kits. My 50 Gallon tank has been running for 5 months now and contains small fishes (like Neon tetra, harlequin rasbora). I didn't get test kits earlier because they are quite expensive here in India and I couldn't really afford them.
However, in the past week I lost a huge no. of fishes (about 15 Neon Tetra, 6 Rummy Nose Tetra & 3 Harlequin Rasbora).

I did almost everything I was supposed to do-- waited first 2 months for cycling; did 25-30% partial water change every week; wasn't overstocked yet; kept 2 filters- one Internal power filter with sponge media and another Top filter with ceramic rings; didn't overfeed; temperature, though did rise about 2-3 degrees in the past 10-14 days, is still at 25-26 degree Celsius which is within the acceptable range for the fishes I have.
I'm completely at a loss... (Although I'd like to mention this death parade started after I added 7 neon tetras & 6 Rummy Nose tetras last week).
Anyways, long story short, I've decided to buy test kits. However, I can afford any 2 of ammonia, nirite & nitrate (the API master test kit, though better & cheaper in the long run is completely out of my budget). Which two should I go for ?

I was thinking Ammonia & Nitrite since, as I've read, the nitrate can be removed by doing water changes. Will that be a good choice ?

Answer
Hi Deep

I know they can be expensive,  but you really need a test kit that will test all parameters ammonia, nitrite, nitrate and pH. Otherwise you may be wasting your time if you're just checking one or two of these.

Also, the internal power filters are a good supplement but should not be considered as a main filter. Make sure your top filter is large enough for a 50 gallon. I always use twice the filtration my tanks require. For example in a 50 gallon, I would get two 50 gallon power filters, or 1 hang on back filter and a 50 gallon canister filter. I have one 50 gallon with large Cichlids in it and I have two 75 gallon filters on that tank.

Finally, two issues are what killed your fish. One, you added too many fish to your tank at once. You should never add more than 3-4 small fish or 1-2 larger fish to a tank at one time to give the filters a chance to adjust to the increased bio load. Add 3-4 small fish, then a week later add 3-4 more if you have space in your tank for them.

Space is what brings me to my last point - if what you are saying is you had 15 Neons, 6 Rummynose and 3 Harlequins in your tank, your tank was already at capacity before you added the new fish. With small fish, you need to consider them 2" of fish per gallon of water. So, 15 Neons would be taking up 30 gallons of water. I have some Rummynose Tetras that are 3 inches long. In simple terms...... 15 Neons, 6 Rummynose and 3 Harlequins are taking up 48 gallons of water. This doesn't include any other fish you may or may not have had in the tank.

Hope this helps get you back on the right track. Good luck!

Richard