Corydoras breeding - cloudy water?

[Freesafety]

I've been struggling with water clarity in one of my 55gal tanks.  It has 2 sponge filters, a Ziss bubble bio moving bed filter, and a HOB Aquaclear running on it.  I typically do a 25% water change weekly.  Last one was 2 days ago.  Following are the water parameters:  ammonia - 0, nitrate - 25, nitrite - 0, GH - 300, KH - 80, pH - 6.8, chlorine - 0.

There were hundreds of endlers in there but I moved most of those fish to outdoor tubs a few months ago (I assumed my problems were because of the high bio-load).  Right now, the tank is pretty lightly stocked with about 24 cardinal tetras, 4 kuhli loaches, 5 albino corydoras, 4 juvenile anglefish, 12 endler livebearers, and 7 juvenile odessa barbs.  There are also red ramshorn snails and ghost shrimp in the tank.  The corys are adults and will breed periodically.  They just bred today and I notice the water is noticeably cloudy and I can see a "scummy" protein layer on the water surface.  Could this be as a result of the breeding?  I'm wondering if there's enough milt released during fertilization to make the tank look cloudy.  Is this a regular thing with cory breeding?  Thanks in advance for any insight.

[Andy's Fish Den]

I have never had my water turn cloudy from fish breeding in it. If I had to guess why the water is cloudy, I would say bacteria bloom. For a 55 gallon tank, that is quite a bit of fish in it, you do have quite a bit of filters running on the tank, but how old is the tank? is it fairly new. Could be food that is being fed and the quantity of food being fed. What I would do is, bump up the amount if water changed to at least 50% weekly, clean the filters and watch how much food you are giving, and see how it is in a couple weeks. 

[Freesafety]

The tank has been setup for 3 years or so.  What you say makes sense though.  It must be a bacterial bloom and just a coincidence that it happened when the corys spawned.  I feed twice a day, primarily Xtreme flakes (taking turns between spirulina and krill), Xtreme bottom wafers (every now and then I'll feed Repashy instead), and BBS every 2 or 3 days.  I'll increase the frequency of water changes to 2 or 3 times/week and cut back some on the food I put in the tank.  Thanks for the help.