I have freshwater fish and Im using a filter(for tank size 10-30 gallon) but I have green algae on side of tank and salt like crusty flaky stuff on outside of tank..I have had the salt like stuff in the past with a different tank.I still can't figure what it is or what causing it..A lady I know who works at a pet store well she ownes it anyway she had me bring her a water sample of my tank.I brought it to her she tested it and said the nitrate level was high..Ive been using ph balance and aquarium salt when I do water changes to prevent from shocking the fish. Algae eaters don't live in my tank cause of nitrate level.So im trying to figure what to do..

first of all, are you actually cleaning your tank, not just changing the water? if you have gravel on the bottom, you need to be cleaning that too. high level nitrates can kill fish very quickly.

Yes ive been taking a algae brush to tank and was using gravel hose thing.It recently stopped working(nvm it just started working again.The nozzle was loose).So im trying to figure out what is wrong with it.My fish can live in high nitrate level.Ive had them for over 4 years.

I just cleaned the tank today.Most of the algae is on the back of the tank(tank is by a window so it might be cause of the sun.).Salt like stuff is a mystery to me.

yeah i get the algae in my tank too, especially where it gets the most sunlight. i've been trying to google it but it comes up with nothing, so i literally have no idea. i guess if you're cleaning it regularly and it's not hurting the fish it might not be an issue? if you're putting salt in the water it may just be like.. some undissolved stuff that's collected or something.

hopefully someone can provide a better answer because i really have no idea D: good luck!

the salt like stuff is on top and around fish tank.On the rims.Its easy to clean up its just odd that its there.im going to get some replacement filters for the water filter unit.Mine is wore out.

The salt buildup is just from the aquarium salt you're using. It's normal, and it's not harmful. Just take the lid off and wipe it down with a damp cloth. It'll come back, but that's just a part of tank maintenance (my tanks get it, too =P).

It's the same thing with the algae growth. You'll clean it off, but it'll keep coming back - and that's normal. That being said, you can slow down its growth by reducing the amount of light the tank gets. Is it placed in direct sunlight? If so, move it. You can also reduce the amount of time the tank's light is on for. Remember: Algae is a plant, and plants need light to thrive. I have mine hooked up to a timer that only has it on for 4 hours each day (in the afternoon, when I'd want to be looking at my fish). Keep in mind that algae isn't harmful, so these tips aren't necessarily needed. I'm just letting you know how you can slow down its growth (it'll still grow, and you'll still need to scrub, just not as often as you do now). If moving the tank or otherwise cutting down the light source would be too much of a hassle, then you can ignore this in favour of algae scrubbing more frequently. =P

Also, as an aside: Nitrates have nothing to do with pH levels. And, from personal experience, pH balance does basically nothing. There are better/cheaper/more efficient ways to alter your pH level (coral to make it harder, driftwood to make it softer) - but that likely isn't something you need to be concerned about anyways. Sorry, got side-tracked: Your nitrate levels could be high from over-feeding your fish (once a day or even every other day is plenty, and be conscious of how much you give them), from over-crowding your tank (too many fish for its size; a general rule of thumb is have no more than one inch of fish per gallon of water), or even from changing too much of the tank's water or doing so too often. You should really only be replacing a quarter of the tank's water once a month. Taking too much out gets rid of the good bacteria that breaks down and lowers your nitrate levels. Also, don't change the filter media (or cartridge) at the same time you change the water. I work on a 2-week cycle; I do both once a month, but every two weeks I'm either changing the filter OR changing a quarter of the water - but never both. It's okay to add more water as it evaporates, just don't be removing any until it's time to do a water change. So, long story short, my advice is ditch the pH balance, alter what needs to be changed, and worst case scenario, buy some bacteria supplement to help get those levels down.

(I worked in the petcare [fish] department of a pet store for 5 years, and I've kept and maintained many tanks and countless species of fish throughout my life.)

Its not in direct light just a very small amount of the tank is against a window.I know a need a new filter cartridge.So far since I got the gravel hose back working everything is fine.I feed them once a day.(half awake not sure if im spelling anything right.)