29 Gallon Freshwater Queries

[Tearie]

Tank: http/i.imgur.com/CWFdRFQ.jpg
 
Hiya, I've had my tank up and running for about 6 months now, here are the details:
 
Nitrites : 0
Nitrates : 25 (water's naturally quite high in nitrates, I use Prime for water changes and Purigen in one of my filters)
Ammonia : 0
PH : 7.9 - 8.2
 
Current stocking is http/prntscr.com/1kqdpo
 
I had a few questions about my tank and it's general condition.
 
Right now the corys are living happily and enjoy a diet of algae wafers and catfish pellets. I understand my PH levels are quite high for them, but is it something to worry about if they're doing fine? Could it be something to have concern over for the other residents in my tank?
 
Initially I had 8 endlers or so, but over time I noticed them dying out, leaving only the 3 I have left. As my tank is so heavily planted I wasn't able to retrieve every fish which I'm sure have either decomposed or been scavenged by the shrimps and corys.  Over time the only big change I made to the tank was removing an interal filter (had a second internal filter running whilst doing this) to clean the filter media in spare tank water. This stirred up quite a lot of muck which left the tank dirty until I could finish putting the filter back in and allow it to clean it all up. I'm wondering if this could have harmed the endlers in someway as I've heard they are quite sensitive fish.
 
This brings me onto the next question about my Endler's eating habits. I've been feeding them freeze dried bloodworms and Tetramin flakes but the 3 remaining endlers seem to do the same for either of the food, which is swim up to surface, take a few nibbles of the flakes/worm and then spit them out. I've tried crushing the flakes up to make them easier to eat but it's very hard to tell if they're eating them. Could this just be a result of the Endlers having much smaller appetites, or is this unnatural for them to nibble then spit? I'm also not sure if I have too much water movement on the surface, it's not enough to make the endlers struggle to swim, but the flakes on the surface rotate quite rapidly, would they prefer less movement?
 
I've also had quite an outbreak of hair algae recently on some of my java fern and other plants. http/i.imgur.com/pVysB40.jpg. My tank lights are on quite inconsistently from day to day, but I do try to keep them on for at least 8 hours at most. I'm not dosing any ferts, excel etc. The algae comes off with some force applied and is a browny-grey in colour.
 
In this picture http/i.imgur.com/ziHR4oc.jpg you can see some other algae that I have in the tank that is trapped between the soil and sand (walstad tank), a greeny algae that can be removed through poking, is this anything to worry about? Ultimately I'm wondering if the algae problems are related to an issue that I've had since the start of the tank, which is that some areas of my sand was too thin, meaning with the corys help, some of the Miracle-Gro - Organic Choice All Purpose Peat Free Compost comes through to the surface of the sand as shown here: http/i.imgur.com/0TS1Kuz.jpg. The corys seem fine digging through the little bits of soil that come up (doesnt make the tank dirty at all, water is still crystal clear) but I'm wondering if it could be affecting my endlers and the PH.
 
Ultimately I want to ensure that the remaining 3 endlers survive and live happily by targetting the food issue, as well as addressing the potential risk (?) of the soil and algae. Lastly is the stocking about right for this tank? Kind of expected more room to play with but I'm open to suggestions for mid-top level fish that can live in high-ish PH levels without making me too overstocked once I get all these problems sorted!
 
Thank you for your time, sorry for the very long post.

 

[Bettabuddy664]

A few questions: How did your other 5 endler's die? If it is some kind of sickness, you should immediately quarantine all of your fish into a separate tank, and do a 90% water change. Also, do you see your endler's acting strange toward each other or themselves? If one is hiding, most likely he is sick. 
 
The algae is fine for the tank and good food for your oto's.
 
Also, the eating then spitting habit is common. My fish do that a lot too, and they just eat the smaller pieces that they spat out >.<.
 
Try and lower your PH just a bit.

 

[Tearie]

I'm really not too sure how the other endlers died, the ones I did manage to inspect had no signs of illness or infections however. I did catch a glimpse of a dying endler and it seemed unable to swim and was close to the bottom of the tank struggling. The remaining endlers are swimming fine, aren't bloated and still swim quite actively towards the surface and around the tank for food. They swim together and independently now and seem normal apart from one endler who's a bit more reserved and has barely any colour (is silver/grey-ish) although I think it's always been quite small and antisocial since getting it from the LFS. How would I go about lowering my PH?

 

[Bettabuddy664]

Driftwood can lower your PH level to a healthy level, if you can't get those, try oak leaves too.
 
Hope I helped!

 

[Blondielovesfish]

Don't bother with changing your pH. pH changing tends to have side effects which can cause stress for your fish (pH fluctuations etc.).
As long as you got your fish locally then they should be fine. If they were bred locally then they will be even better