Newbie with Old Tank Syndrome

[PestyNinja]

Little bit of background: My mother has a 20 gallon tank that actually started out as my father's. When he stop taking care of it to focus on his larger tank, she got some kind of tetras (white ones, not mollies though) threw them in there and they have been living there for many years (with a few replacements, maybe). She feeds them and rubs the inside of the glass with a brush sometimes, but has never once done a water change in 10+ years.

This summer when my nephews came over to stay with us they asked if they could get more fish for the tank, since there was only three fish. Not knowing diddly squat about aquariums other than you have to feed the fish, I said, "of course". Little did I know what was going to happen. Most of the fish we got died within a month. But we still had:

2 ? old tetras
3 black skirt tetras
2 ? catfish, smallish gray ones with darker spots
1 kuhli loach
1 mystery snail
1 dwarf african frog

Now that the boys are gone and I have more time, I figured I'd "fix" my mother's tank for her. I'm not attached to the fish but I love my mother's little frog! Although, weirdly, I'm terrified of frogs and he still freaks me out a bit.

On Wednesday night I read up a little on kuhli loaches and black skirt tetras. I read that black skirt tetras need to have at least 5 fish or they get stressed and the same for kuhli loaches, they don't like being by themselves. So yesterday (Thursday) I went to Petsmart and bought a 5 in 1 test kit, 4 black skirt tetras and 1 kuhli loach.

I was shocked by the test results:

gH: 180
kH: 40
pH: 7
NO2: 0
NO3: 200+ off the charts

I knew something was wrong with the tank but I didn't think it was off the charts bad. I really wish I hadn't bought more fish, too. I had thought I would do the test see what was wrong, buy some chemicals and put a little bit of this and a little bit of that and presto chango, happy fish.

I went home last night and did some reading up about my test results and figured out that I have "old tank syndrome." There are so some different things people say to do and people saying, "if you do what that person told you your fish will die." I really need some help. It's a bit much really and I was really freaking out about doing the water change, but it really wasn't hard at all, thankfully.

I had read to do water changes from anywhere from 50% to 10% for the problem I have. The nitrogen cycle is still a mystery to me, but from what I understand/read if you do a 50% water change you'd mess that up, right?

I did a 10% water change today, but do you guys think I can be more aggressive without killing the fish/messing up the nitrogen cycle? There is really A LOT of nasty stuff in the gravel, I got about a 2" x 2" spot clean today, but at this rate it's going to take weeks to clean the bottom. But I'm willing to do small daily water changes if that's what's best, but I really don't want to lose the frog. I read to do 10% for three days, then 20% for three days then 30%. Or at least that was what I thought sounded like good advice. But I don't know.

Can an African Dwarf Frog live in these kinds of conditions for that long?

I don't want to use any chemicals (unless I need to?) I think I should just focus on the getting the nitrates down while keeping an eye on the pH and NO2, right?

Can I just ignore the gH and kH problems for now? Or should I use bottled RO water? I just read 1/2 RO water 1/2 tap water should be used to help, is straight RO water too much of a shock?

I'm squeamish with nasty gunk, would it be okay if I bought a new filter and put the old filter cartridge in it? I'm sure it needs to be cleaned but that's the last thing I want to do!

I read that you shouldn't clean a filter on days that you do a water change. They mean the filter cartridge, right? Is that true? Should I skip a water change tomorrow and clean the filter cartridge?

All this stuff seems so complicated. Sorry for the long post, I hope I can get some of the answers I need! Thanks so much!

 

[Iodizedfate]

If you change the water too much too fast you can put the fish into shock. I would do 10% water changes every day for a couple weeks, then maybe move it up to 20%. When the toxins build up over time the fish sort of 'acclimate' to it and any drastic change could stir up some gunk that could kill them.

It looks like you have a good idea of what to do to fix it.

Things you need to watch out for are PH fluctuations and extreme changes to the tank. Slower is better in a situation like this.

You can absolutely put a new filter in with the old one. Let the bacteria build up on it for a couple weeks and you should be able to pull the old one out.

I would just use tap water for right now. You can use RO water but it doesn't have any nutrients and minerals that the fish and bacteria need to live. As long as you use a dechlorinator you should be fine with tap.

continue to clean out the gravel as you do your water changes, this will remove old waste and help bring the perimeters to normal.

Ideally you want ammonia and nitrite (NO2) to be 0 and nitrate (NO3) to be less than 20ppm

Once you have the NO3 where it isn't off of the scale you can start doing larger water changes to bring it down faster.

gH and kH are usually used for saltwater tanks or breeding certain types of fish. I don't even have tests kits for those.

 

[blert]

I agree that it sounds like you have a good plan. Start with small water changes daily and gradually increase the size of the water change until you hit 50%. BTW, doing a 50% PWC or larger will not effect the bacteria at all. They live on the filter media and the surfaces of the things in the aquarium not in the water column. After you get the nitrate to a good level (below 20-40 ppm) you can slow down to doing 50% PWCs a week.

If you get a new filter either run both for a month or try to fit your old media into the new filter. Honestly, IMO, even if you tossed the old filter/media and put a new one on I don't think you would have a problem in a tank that established but it is better to err on the side of caution.

The nitrogen cycle is easy:
Waste breaks down to ammonia,
Ammonia is converted to nitrite,
Nitrite is converted to nitrate,
Nitrate is removed from the system by PWC or plants.

BTW, please test your tap water for ammonia, nitrite, nitrate and pH. This will help you know what to expect after a PWC.

 

[Alyxx]

I agree, you seem to have a good handle on how to fix this. Slow and steady is the key here. What dechlorinator are you using? I would definitely recommend that you pick up a big bottle of Prime. It is an excellent product, and it is way more cost effective than almost any other dechlorinator on the market. You only need two drops per gallon of water, so with all the water changes you will be doing it will save you lots of money in the long run. Don't worry about RO water or the GH and KH. Most fish are very tolerant of a wide range of hardness in their water, so stability is more important than the actual level in the majority of cases. Same with ph. Be sure to keep an eye on the ph to make sure it doesn't swing too much with the water changes. Have you read the articles on the site about cycling? They will help give you a better idea of the nitrogen cycle and how it works. As for cleaning the filter, I think what you were asking was if you could buy a new filter and put the old cartridge in it, then just toss the old filter (actual piece of equipment) out, right? That would be fine. The beneficial bacteria are mostly in the media/cartridge. Just be sure to occasionally swish the cartridge in some old tank water while doing a water change to clean some of the debris off of it, and don't throw it out until it is literally falling apart. When it looks like it needs to be replaced, run a new cartridge next to the old one for a week or so before you throw the old one out.

 

[Bbarb27]

It sounds like you've read up on OTS and are trying hard to remedy the situation. I hope you get things under control and don't lose the frog. I had OTS in a tank of mollies and didn't realize it until I did a massive cleaning and lost many of them. Slow and steady changes will be much easier for your fish/frog, even though the temptation is there to get everything nice and clean right away.

 

[PestyNinja]

Thanks for all the help guys! And just a few more questions...

I'll keep doing the small PWC's until the nitrates look better. Then I'll do 50% water changes. How often do I have to clean the gravel once I get it all cleaned out? There is a lot of stuff (shells and decorations) and it's going to be a pain to keep moving them around. Do you really have to move all that stuff around all the time?

If the pH does start changing, I just stop doing PWC's until it goes back, right? I think I read that some place, but can't find the page anymore.

I went over to my parent's house today to do a 10% water change. The pH was the same and I didn't notice until I got home that I don't have a way to test for ammonia! All the fish were alive though, so I doubt it's bad. I guess I have to go buy one? Or can I just assume it's fine in such an old tank? We've had fish in there for 30+ years now.

I didn't even think to test the tap water, so thank you. It turned out to be:

pH 7.5
NO2 0
NO3 <20

I guess that means that eventually the pH should go up to 7.5 and that's fine?

My parents are on well water so I don't have to do anything to it, right? I can't really ask my dad for too much help since he doesn't like me messing with the tank, but I did tell him the other day, "Dad, did you know you're suppose to treat the tap water before you put it in the tank?" And he was like, "You dummy, we're on well water so it's fine!" And the funny things is, years ago when I had a betta fish, I'm sure I was treating the water for chlorine! It's a good thing I brought it up to him too, because I was going to buy a dechlorinator.

The whole filter thing still has me totally freaked out. I don't even want to touch it! I really don't want to mess anything up or break anything, I suppose. Anyway, I noticed today that the top that goes on the tank only has a spot for one filter so I'm not going to be able to run two at the same time, even though I like that idea. I think I will try to buy the same type/model filter that we have now so I can use the same cartridge, just to be on the safe side.

Thanks again!

 

[blert]

Vac a section of the gravel each time you do a PWC, that will make it a bit easier on you. If you don't then a lot of gunk will build back up.

Your pH will level out and stay stable once you get to the point of 50% PWCs weekly.

Well water doesn't need a chlorine remover but there can be heavy metals and such. I still recommend using a conditioner. Prime is just about the most cost effective one you can get as it takes only a very little bit (2 drops per gallon I think it is).