Need help on small and large aquarium. Fish possibly dying.

A little back story...my elderly neighbors bought a small (roughly 2 - 2.5 gallon) aquarium a year ago. It has a small sponge filter, a mini heater and they stocked it with guppies and snails. A few weeks ago they were on vacation for a week and had me watch it for them. At this point there were two guppies and a single snail left. My only job was to feed them. I have no clue how they kept their aquarium but only found out recently they had many fish and snails die on them that they kept replacing. To my knowledge, the only thing they ever did was just top the aquarium off with tap water. No treatments or anything.

A few days after their return, one of the guppies died. A few days after that the second guppy gave birth to 7 babies then shortly after died. My neighbor was frustrated and gave me the aquarium for my kids and I to keep. I know NOTHING about keeping fish at this point so went into an internet research craze for a few days. We decided to get a bigger aquarium and do things right from the get go. I set the larger aquarium up and I'm basically into the nitrogen cycle by a week. I have live plants and I've checked the aquarium water levels every other day. Below is the current new setup with the most current water scores.

New Tank:
Tank: 37 Gal. Top Fin (30" L x 12" W x 22" H)
Filter: Top Fin Silentstream 40 (This is being replaced with a Seachem Tidal 55 in a couple of days.)
Light: Current USA Satellite LED Plus Pro
Heater: Top Fin Submersible 200W
Substrate: Gravel
Plants: Java Moss, Java Fern, Anubias, Anacharis and Hogwort

Current New Tank Water Tested 09/22: (Tested with API Master Kit)(Original Tank Setup Date was 09/13)
Type: Tap
Water Treatment: Top Fin - Aquarium Water Conditioner
Bacterial Treatment: TLC - Aquarium Optimizer
Liquid Fertilizer: API - Leaf Zone
pH: 7.6
HR pH: 7.4
Ammonia: .25 ppm
Nitrite: 2.0 ppm
Nitrate: 5.0 ppm (This is the only number to have changed since the original aquarium setup date of 09/13. Original number was 10)
Current Temperature: 83.5F (The tank was around 76.8F since the original setup, I raised the temp because I was told this would help with bacterial growth.)

*I've been putting some fish food in daily to help with the nitrogen cycle? Not sure if this is how it is done.

So today after testing the water of the new tank I decided to test the water of the small tank for the first time, for some reason the thought never cross my mind. I realized the Nitrate was off the chart and the only thing I read that I could do at this moment was a water change. The small tank water was as follow:

Small Tank Water:
Type: Tap
Water Treatment: Top Fin - Water Conditioner (When receiving the aquarium I did top if off with treated water.)
Bacterial Treatment: None
Liquid Fertilizer: API - Leaf Zone
pH: 7.6
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: 160+ ppm

I did some quick reading and realized a 50% water change might not be enough. So in the meantime I decided to put the baby guppies and snail into the large aquarium so I can work on the smaller aquarium. After about 30 minutes in the larger aquarium, 1 of the 7 guppies disappeared (we think it died and is somewhere in the forest of plants now). The other guppies have been hanging out near the top of the aquarium, they rarely go down. The snail immediately climbed up the glass and hung out for a while. Fell down and climbed back up and is staying near the top.

After the small aquarium water change, I filled it back up with treated water and let it run for a while. I rechecked the levels which were all the same accept the Nitrate which went down to around 20-40ppm. Do I need to treat this more before putting the small guppies and snail back? If so, how do I bring the Nitrate down further? Or, should I just keep the guppies and snail in the big tank for now and see how that goes? Additionally, is it common for baby guppies and snail to group up at the top of the water? When they were in the smaller aquarium, they seemed to hang out all over the place.

Thanks ahead of time for any advice. Sorry for the long write up, I just felt like the more information you guys had, the better advice I could get and I didn't want to leave any stone unturned.

 

Welcome to Fishlore. Looks like you're off to a good start.
The new tank appears to be in mid cycle. Putting the fish in the new tank will result in a fish - in cycle.
Nothing wrong with that. Keep watch on the fish & if they looked stressed, make a 10% - 20% water change.
Hang in there & expect to lose a few fish as the cycle reaches completion. Should take five or six weeks.

 

Do you still have the filter for the 2.5 gallon? I'm asking this because it seems to be cycled going off of the test results (no ammonia or nitrite but nitrates are present). This means you could move the old filter into the new tank and it will Jumpstart the cycle since the bacteria is already present in the filter.

If the filter media used in the new filter are those crappy carbon cartridges, I'd advice you to throw them out and switch them with just sponges or sponges and bio ring, it will be cheaper in the long run as they don't need changing and they're more effective. I'd personally buy a aquaclear 70 over a seachem tidal as it already comes with sponges and bio rings.

I wouldn't put the guppies back in the 2.5 gallon, just perform a 50% water change on the 37 gallon to reduce the ammonia and nitrites (you want both to be under 1 during cycling). Once your tank cycles, you won't have ammonia and nitrites and can lower water change frequency to weekly.

Also lower temperature, it does encourage bacterial growth but that's to be used when nothing is in the tank. Anacharis usually does terrible in temperatures like that and the fish would do better in cooler water (75-80F)

 

I do have the old sponge filter. I can throw that into the new tank tonight.

Regarding the new filter media, yes, it is a carbon filter and I've already replaced it once because the water keeps bypassing it due to it getting clogged or something. I don't have any sponges for now, but I can go get something tomorrow. Regarding the Tidal 55, I got it mainly due to the self priming pump. We have a lot of power outages where I live. Just yesterday we had 4-5 brown outs. So that was my main reasoning for getting one.

Should I do a 50% water change on my tank tomorrow? I read you wanted to see the ammonia spike, then go down. I haven't seen an ammonia spike. The only real number change I've seen is my nitrates go down a bit.

 

I do have the old sponge filter. I can throw that into the new tank tonight.

Regarding the new filter media, yes, it is a carbon filter and I've already replaced it once because the water keeps bypassing it due to it getting clogged or something. I don't have any sponges for now, but I can go get something tomorrow. Regarding the Tidal 55, I got it mainly due to the self priming pump. We have a lot of power outages where I live. Just yesterday we had 4-5 brown outs. So that was my main reasoning for getting one.

Should I do a 50% water change on my tank tomorrow? I read you wanted to see the ammonia spike, then go down. I haven't seen an ammonia spike. The only real number change I've seen is my nitrates go down a bit.

I understand I have lots of power outages too, that's why I run a sponge filter in each tank just in case.

Since you have nitrite present (and in large quantities) you have either already had the ammonia spike (this is because in order for nitrites to "naturally" occur, they need to be processed by the good bacteria from ammonia to nitrite) or nitrites are in your source water. I would test your source waters nitrite to be sure but I suspect it's the former.

 

I understand I have lots of power outages too, that's why I run a sponge filter in each tank just in case.

Since you have nitrite present (and in large quantities) you have either already had the ammonia spike (this is because in order for nitrites to "naturally" occur, they need to be processed by the good bacteria from ammonia to nitrite) or nitrites are in your source water. I would test your source waters nitrite to be sure but I suspect it's the former.

I just put the sponge filter into the large aquarium. The only thing left in the small aquarium is the mini heater and a few plants. I'll replant them tomorrow.
I am going to check the tap water and test it right now. Should be done with that in about 15 minutes.
Tap Water Testing Results:
HR pH: 7.4
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: 5.0 ppm

 

I just put the sponge filter into the large aquarium. The only thing left in the small aquarium is the mini heater and a few plants. I'll replant them tomorrow.
I am going to check the tap water and test it right now. Should be done with that in about 15 minutes.
Tap Water Testing Results:
HR pH: 7.4
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: 5.0 ppm

So I did a 50% water change today and rechecked water levels. This is what I am currently at.

HR pH: 7.6
Ammonia: 0 ppm
Nitrite: .25 ppm
Nitrate: 5-10ppm

Another issue I had was a white fuzzy fungus starting to grow everywhere and rapidly. I talked to my local fish store and was given 6 Amano Shrimp to help curve the fungus growth until the water becomes more balanced.

How often should I be doing water changes and how can I keep my Ammonia, Nitrites and Nitrates down until the tank becomes established?

 

So I did a 50% water change today and rechecked water levels. This is what I am currently at.

HR pH: 7.6
Ammonia: 0 ppm
Nitrite: .25 ppm
Nitrate: 5-10ppm

Another issue I had was a white fuzzy fungus starting to grow everywhere and rapidly. I talked to my local fish store and was given 6 Amano Shrimp to help curve the fungus growth until the water becomes more balanced.

How often should I be doing water changes and how can I keep my Ammonia, Nitrites and Nitrates down until the tank becomes established?

I was told water changes only when the ammonia and the nitrite combined hits 0.5ppm as you're cycling. Then you do 30-50% water change to drop it back down. I was checking every day to every other day on the levels when I did my tanks. The Nitrate looks good though, so once you get the Nitrite to 0 and Ammonia to 0, keep an eye on it for a while. If they don't change, then your cycling should be finished. After that, do water changes (I do about once a week) to keep the Nitrate below 20-40ppm. The fuzzy white fungus is normal though and goes away on its own, or your shrimp will happily enjoy it. It's a sign of bacterial bloom.

 

Update: As of now, I think I'm down to 4 (possibly 3) out of the 7 guppy fry I started with. I know one died within an hour of the original transfer. I lost two more over the following night and maybe 1 more over last night. Yesterday morning I checked the water again. I had the following readouts:

Ammonia: .25
Nitrite: .50
Nitrate: 5.0

So I did a second 50% water change. I checked the water again sometime after the water change and got.

Ammonia: 0 - .25
Nitrite: 0 - .25
Nitrate: 5.0

I know my Nitrate will always be 5.0, that's what my tap water has to begin with. So I did a check today and my Ammonia was 0, Nitrites were at .25 and Nitrates we're at 5.0.

Would those numbers mean that my Nitrosomonas are being established, but we're still waiting for Nitrobacter? Until then I'll keep up with water changes when the Ammonia and Nitrites hit a combined .50

 

Update: As of now, I think I'm down to 4 (possibly 3) out of the 7 guppy fry I started with. I know one died within an hour of the original transfer. I lost two more over the following night and maybe 1 more over last night. Yesterday morning I checked the water again. I had the following readouts:

Ammonia: .25
Nitrite: .50
Nitrate: 5.0

So I did a second 50% water change. I checked the water again sometime after the water change and got.

Ammonia: 0 - .25
Nitrite: 0 - .25
Nitrate: 5.0

I know my Nitrate will always be 5.0, that's what my tap water has to begin with. So I did a check today and my Ammonia was 0, Nitrites were at .25 and Nitrates we're at 5.0.

Would those numbers mean that my Nitrosomonas are being established, but we're still waiting for Nitrobacter? Until then I'll keep up with water changes when the Ammonia and Nitrites hit a combined .50

I'd agree that you're still waiting for the bacteria that converts nitrites into nitrates. You may lose all your fry as they don't handle Ammonia and nitrite concentrations well. Just keep doing what your doing.