Thoughts on my chemistry and cheap ways to improve it

[jcurella]

I recently moved and had to downgrade my system.
I had a 75g display with a 40g refugium.
I am now running a 40 gallon as my main tank with no refugium.
Been in the new place now for a month and tested what I could for the first time.
This is my current setup, and the test I took with my current testing kit.

40g tank with dual bio wheel HOB with phosban and "carbon zeolite" mixture.
And the protein skimmer I had for my 75 which is actually rated for like 150g.

Tank parameters are as follows:
ca2+ is 460
PH 8.0
Ammonia 0 ppm
Nitrite 0 ppm
Nitrate 20 ppm
Salinity 1.016
(I know this is hyposalinic, but i've read this is ok in the past.)

Everything seems to be doing fine.
Tank is stocked with about 30 lbs of live rock, and a 4-5 inch sand bed. lots of copepods are visible (never seen any in my last system but they are thriving in this set up for some reason.)
3 damsels, a 7 inch engineer gobie, 1 clown clown fish, 2 mollies that I acclimated to salt water, 7 small hermit crabs, 2 zebra snails,

What should I focus on next? I used all the tests for the kit I have. What would be the next important test kit to purchase?
Funds are low right now so I am getting by with the bare minimum.
Any thoughts on what I could do on a budget to optimize my system more?
I won't have any funds for salt for about a month, so water changes are out of the question for now. All I can do for the time being is top it of with RO water until then.
I have two huge rubber maid bends full of filtration, tubing, pumps etc.
But I think I've put the best filtration system together for the time being.

Advice?

 

[heathlindner25]

I would suggest adding more salt to your system.

 

[bertoni]

Personally, I agree with raising the salinity to 1.0264 over a period of a couple weeks. The animals we keep generally are from ocean areas, not brackish waters.

 

[jcurella]

Thanks for the advice.
I was told by a lfs owner a long time ago that hyposalnity wasn't that big of a deal.
To be honest I've always ran my tanks a little hypo since that conversation with no problems (that I am aware of.)
I've been looking into it more since I posted this and it seems a lot of people lower salinity for treating ich.
From what I've read, the short term affects aren't that bad, but long term affects can be harmful to the fishes equilibrium and kidney functions.
I'm in between jobs right now and literally have no money for salt.
I will make it a priority to at least get a small 10 gallon box as soon as I can.
I've also noticed that evaporation has affected my salinity greatly in this smaller tank now.
It has already went up from 1.016 to 1.018 since I measured it yesterday. Maybe I should just stop topping it off until I get some salt?
I haven't tested anything else today except salinity, but I am now wondering what effects the evaporation has had on the other parameters.
This is the smallest system I have ever ran so I didn't even think about how the affects of evaporation would concentrate parameters so much.
Once I get some paychecks coming in I think I might set up a 20 gallon sump just to increase the gallons of my system.
Does this sound like a good idea?

 

[bertoni]

Letting the water evaporate to raise the SG is fine as long as the total water volume is acceptable. I'd be cautious if the animals are doing well enough as is.