[Malachite green for columnaris?]

I malachite green is used in treatment of ich and unicellular parasites on skin and gills it will have no effect on columnaris 

[Quarantining New Fish and Medicating Display Tank]

I Qt  all new fish but I only treat wild caught fish for parasites and I just monitor for 4weeks before adding to my main tanks

[white spot above eye on Red Eyed Tetra]

It could an injury or a bacterial infection  i would qt and  treat with aquarium salt 1 table spoon for 2 gallons for 5days if no improvement or it gets worse treat with maracyn  or maracyn2 

[Zeiss Bubble Filter Air Bubble Noise]

I  use a ziss 300f bubble filter I find turning down the power on my pump is the only thing that affect the noise level

[New to forum, fish keeping, & African Cichlids]

I would get I some more   cichlid caves and place them in the corners and back of the  aquarium

[New to forum, fish keeping, & African Cichlids]

You can try removing all the fish and rearrange  décor the and put the fish back put the most dominant fish in last so he doesn't have time to set up a territory

[Wasting Disease]

Most rummynose tetra are wild caught  so they often have parasitic infections

[Wasting Disease]

You could be dealing with a internal parasitic infection 

[New to forum, fish keeping, & African Cichlids]

 What you  need is plenty of caves and décor to break up sight line  to give less dominant fish  place to hide and  rest 

[good dither fish for my tank]

It difficult to put smaller dither fish in with is Oscars because they will eat anything that fits in there mouths from my experience they should be ok with the fish you have

[Columnaris?]

I don't think its columnaris it looks like a hole  it could be an injury parasitic infection  I would treat with aquarium salt 1 table spoon for 2 gallons for 5 days if no improvement or gets worse use API general cure

[White protrusion and dark spot on side of Rummynose]

It could be a parasitic infection if you have access to Esha gdex active ingredient is praziquantel and aquarium salt 1 table for 3gallons  at that level salt will harm  your live plants

[Nitrate levels in planted tanks]

I would increase the group of glow tetras

[Columnaris?]

From the pictures it difficult to tell what is going on  the odd swimming Patten could be swim bladder problem

[75G Six Months In]

Nice tank

[Best Canister Filters]

I put silicone lubricant on my o ring and gasket once a month when I do my filter maintenance

[New to forum, fish keeping, & African Cichlids]

What type of Africa cichlids do you have  and what size  is your tank 

[Angel Fish Fin Separation]

As erythromycin has not work work I would treat with aquarium salt 1 table for two gallons for 1week and API general cure 

[Neon tetra and super blue emperor tetra nips beta tail.]

Have you got a separate tank to put the Betta in

[Creating a new Guppy Strain...]

Nice looking guppys

[Cloudy water]

Definitely looks like algae bloom

[Purple Dots On Glass]

It could be some sort of fungus 

[Snail Indigestion]

I use shimp king snail pellets

[Black water tank]

8 hours ago, MickS77 said:

I have hard tap water as well. I don't worry about it and just focus on aesthetics, the Tetras do fine in hard water. I have Lemon, Pristella, Flame, Redeye, and Serpae Tetras in the tank.  

Great tank

[Black Beard Algae]

I spot treat with seachem flourish excel