So I assume you had quite a loss of fish due the vinegar wash?
1, OVERFEEDING: My major mistake, which continues to be a problem, is overfeeding my fish. After 4 yrs I still can't seem to get a feel for how much to feed, especially when I have a tank of fish of multiple species - some requiring specialized food (like algae wafers) only to find that ALL the fish are now consuming the algae wafers while my shy algae dependent fish will usually wait to eat until things settle down in the tank or until night time to eat them. So unless you want to get up and feed your night feeders at 3 am, then you're kind of stuck with having excess food littering the ground while you're just guessing if the night feeders got enough to eat that night. I've got 6 adolescent plecos (only 4 inches long instead of 8) that will eat some flakes and pellets but mainly rely on algae wafers to keep healthy. They are shy, slow eaters so the "2 minute rule" where you only put enough food in the tank that can be eaten in two minutes and then remove the excess doesn't apply to these guys - the pellets are also hard as a rock so I've started presoaking them in some tank water before feeding them to my fish - that allows the plecos to start eating the algae wafers almost immediately. Now once they are full grown, they probably will have enough jaw strength to eat dry wafers. . Of course pre-soaking the wafers also allows all the other fish in the tank to start eating them immediately. My only other tank at the moment has nothing in it but DoJo Loaches that i swear would eat until they burst. At feeding time you would think you had a tank of piranhas (but thankfully they are such peaceful fish they rarely attack each other although they may nudge others out of the way to get to the food - especially if I'm feeding them their favorite food shelled peas - if you've ever tried to remove the shell off of a cooked pea you'll find you create quite a mess, so it's better to purchase frozen peas and cook them for about 1 minute - then shell them)
In my DoJo tank there is never a speck of food left on the tank floor, yet I have had more problems with their tank water than I have with my overfed community fish tank. I think that is due to the HUGE amount of waste generated by these fish (just like goldfish), rather than overfeeding. So keep in mind what goes in is directly related to what comes out. So they are not being overfed they are just really big eaters. This is why I have spend over 1K in purchasing a 90 gallon tank, a cannister filter ($300), and about $400 in 180 lbs of sand substrate. (DoJos like to dig and the digging of even the soft clay gravel was causing damage to their nearly scaleless skin, all of this for 4 fish. Books and some owners say they only grow to about 8 inches long but only 1 of my DoJo's (Baby-boy) is only 8" long and skinny like a snake. My other DoJo's are already 12-15" in length with a max size of up to 2 feet long.
2. OVERSTOCKING: I personally am not guilty of this but I see so many pictures and videos where there are TOO MANY FISH in the tank. I think the rule of 1" of fish per gallon is pretty good. That means that if my 4 DoJos all reach 24" long then I'll STILL be overstocked with a 90 gallon tank.
3. NOT PAYING ATTENTION TO THE FISH REQUIREMENTS (specifically PH and GH - water hardness and temprament). Our city water average ph is 9.4 while most tropical fish need between 6.5 and 8 PH. I have tested my water and it tests at over 9 PH. I use a chemical that is added to EACH bucket of water that contains a chemical the adjusts the PH to exactly 7.0. I do NOT pour in PH 9.4 water and adjust it afterwards. That means I cannot use the Python tool for water changes because it assumes that you can add conditioner or any other chemical or treatment either before or after the water change. Sorry, it doesn't work that way. I refuse to dump PH 9.4 water on the heads of my fish that require a PH of 7.0 knowing that I'll "fix it" after the water change. It doesn't work that way. So unless you're on well water that lacks chlorine or chloramines the do NOT use a tool like the Python. I am sure many people will disagree with me because they are really popular. Many people use it and get away with it but I assume they don't have PH 9.4 water or they know they dont have chlorine or chloramines in their water. I AM guilty of ignoring water hardness or of making all sorts of rationalizations - like "well my water hardness is close to what they require". I am a HUGE fan of Gourami but I really need to face it - they have all lived short lives because they require softer water than what I have. So no more Gourami for me. It's just cruel to seriously shorten their lives. So BEFORE you go fish shopping research out what each species needs in terms of PH and General Hardness as well as their disposition. Go to fish stores where the staff are knowledgeable about their fish and won;t sell you fish that may be too aggressive for your tank or have completely different water requirements from each other - they either don't know or don't care. In my city we have one mom and pop store that just doesn't care, as long as they make the sale. The other two are big box stores where their fish staff are not well trained (but don't just make that assumption, there is a guy at one of our big box pet stores that is highly knowledgeable about fish. There are some beautiful fish out there that many fish store will sell you - you bring them home and find out they are terribly territorial and aggressive and the rest of your tank are all "peaceful" fish that are now being killed or attacked right and left. I do recommend to any beginner that they start with a tank of PEACEFUL fish and do not add any aggressive stock until you know more about what you are doing. Make sure you take a list of commonly found peaceful fish - if the store doesn't have any of them then don't buy any fish that day. Personally, since I'm mostly housebound, I do nearly all my fish shopping online and there are some very good and reputable online fish stores. They can typically carry a huge variety of fish because they don't have to pay for a storefront. There probably are some bad ones too but so far I haven't run across any except on Ebay (sorry Ebay fans but there are just too many scammers there now). LIveAquaria.com is a decent fish store but be prepared to pay $30 or more for overnight shipping and lately they seem to be out of stock on a lot of fish - they used to never be out of stock on anything but maybe the word is out about them. I've never had a DOA fish from them and I've never had a sick fish from them. They have emailed me saying there will be a delay due to disease in one of their tanks and they cannot sell those fish right now. Also make sure you read each stores warranty terms - most want pictures of any dead fish within a few hours after you receive them and then they will refund you or reship another fish (new shipping fees). They use insulated styrofoam coolers and add heat packs or ice packs depending on the season. You pay a dollar or two extra for these things but if you decline you void your warranty should you get a dead fish. Some starve their fish for 2-3 days before shipping to lower the chance of any poop contaminating their water . I've had good luck with Arizona Gardens, and Imperial Tropicals . There is a store called AquaticArts.com I'm going to check out for my next order - they are one of the highest rated on the Internet,
4. FORGETTING TO ADD WATER CONDITIONER: Because I'm disabled I have an assistant that I pay to handle all water changes (I still end of doing some myself but not many) - twice we were doing a water change and at one point after adding water fish began just dropping dead. She swears she added water conditioner and I was standing there talking to her (we're good friends) I swear she did too - but we probably got to caught up in our conversation because we can't come up with any other explanation for the sudden loss of about 15-17 fish each. The others were a little more hardy and survived but I lost some very much loved and in some cases very rare fish. It's the only explanation we have as to what happened because we don't know any other reason for fish to suddenly drop dead right after you add waterl We both still feel terrible. So PAY ATTENTION to what you are doing when you are working with the fish water - their life depends on it.
5. ADDING TOO MANY FISH AT ONCE: I am truly guilty of this, especially when shopping online where it costs $30 to ship whether you by one fish or 10 fish. This is especially true if you just got your tank, it's all nice and cycled and you're ready for all your dream fish. So you buy the whole tankful at once and over the next week or two they start dying off. This is because you have a newly cycled tank with the minimum amount of bacteria and the number of bacteria is only sufficient for 1-4 fish. Your tank is not ready to handle 10-15 fish. So buy a couple of fish and wait a couple of weeks at least (and add another bottle of bacteria) before you go out and buy 10 more fish. Or, as they did in the "old" days just wait and keep adding small numbers at a time forever.
6. POURING THE WATER IN TOO FAST: I've had two different assistants and each time forgot to tell them when they do a water change pour the water in SLOWLY especially if the water level is low - the first time they both just dumped a whole bucket in and fish went flying everywhere in the water and hit their heads and bodies against the sides of the aquarium. it would always kill a couple of the smaller fish and I'd never see them do that again.
There are a zillon other things I've heard others do wrong that I haven't done wrong so it will be interesting to see what others add to this thread.
Jan (from land locked Kansas USA)
